Color filter and process for producing the same

ABSTRACT

There is provided a color filter which comprises a transparent substrate, a picture element part provided on the transparent substrate by the predetermined pattern of a plurality of colors with an ink jet system, a shading part provided on a border part of this picture element part, and a wettability-variable layer, in which the wettability can be changed, provided for forming the picture element part or the picture element part and the shading part.

BACKGROUND OF THE INVENTION

The present invention relates to a color filter which is obtained bycoloring a picture element part with an ink jet system and which issuitable for a color liquid crystal display and a process for producingthe same.

Recently, there has been a tendency that a demand for a liquid crystaldisplay, particularly a color liquid crystal display is increasing withthe development of a personal computer, particularly a portable personalcomputer. However, since this color liquid crystal display is expensive,a demand for the cost-cut is getting higher and, in particular, a demandfor the cost-cut of a color filter weighing in a respect of cost ishigh.

In such a color filter, a liquid crystal usually operates as a shutterby equipping with three primary colors of red (R), green (G) and blue(B) and switching ON and OFF of an electrode corresponding to eachpicture element part of R, G and B and the color display is performed bytransmission of the light through each picture element part of R, G andB.

As a process for producing a color filter which has hitherto beencarried out, there is, for example, a dyeing process. In this dyeingprocess, a water-soluble polymer material which is a material for dyeingis first formed on a glass substrate, which is patterned into thedesired shape by a photolithography step and the resulting pattern isdipped into a dyeing bath to obtain a colored pattern. This is repeatedthree times to form a color filter layer consisting of picture elementparts of R, G and B.

Alternatively, as an another method, there is a pigment dispersingmethod (color resist method). In this method, a photosensitive resinlayer in which a pigment is dispersed is first formed on a substrate andthis is subjected to patterning to obtain a monocolor pattern. Further,this step is repeated three times to form a color filter layer consistof picture element parts of R, G and B.

As a still another method, there are an electrode position method and amethod of dispersing a pigment in a thermosetting resin and performingthree times printing of R, G and B and, thereafter, thermally curing theresin. However, in any method, the same step needs to be repeated threetimes for coloring three colors of R, G and B, and there is a problemthat the cost is high and a yield is decreased because of repetition ofa step.

As a process for producing a color filter which has solved theseproblems, there is proposed a method of blowing a coloring ink with anink jet system to form a colored layer (picture element part)(JP-A-59-75205). In the publication, there are disclosed a method inwhich a convex part which is a border is printed in advance with amaterial having the worse wettability on an ink when an ink having thebetter wettability on a glass substrate is used, and a method in which apattern is formed in advance with a material having the betterwettability on an ink to help the ink fixation when an ink having theworse wettability on a glass is used. However, there is no descriptionregarding how to specifically coat a material having the betterwettability and a material having the worse wettability.

On the other hand, as another process for producing a color filter byblowing a coloring ink by an ink jet system to form a colored layer(picture element part), there is disclosed a method of treating aconcave part with an inkphilic treating agent in JP-A-9-203803. In thismethod, a convex part is formed in advance on a substrate and thisconvex part is made to be ink-repellent and, thereafter, the wholesubstrate is surface-treated with the inkphilic treating agent. However,in this method, since a convex part needs to be ink-repellent in advanceupon the inkphilic treatment, there is a problem that two timestreatments of the ink-repulsion treatment and the inkphilic treatmentneed to be performed.

In addition, as a method for producing a color filter by forming acolored layer with an ink jet system, there is described a method offorming a colored layer (picture element part) by providing an inkabsorbing layer on a substrate and making a difference in the inkabsorbability of this absorbing layer between an exposed part and anunexposed part in JP-A-8-230314 and JP-A-8-227012. However, in thismethod, since a colored layer is formed by forming an absorbing layerand adsorbing an ink in this absorbing layer, there is a problem that adifference in the coloration between a central part of an ink dot and asurrounding part of that is present which results in the colornonuniformity. In addition, there is also a problem that this absorbinglayer needs the predetermined thickness resulted from its function ofabsorbing an ink.

The present invention was done in view of the above problems and a mainobject thereof is to provide a color filter in which a part having thebetter wettability and a part having the worse wettability can be formedon a single layer regarding the wettability of a substrate which becomesproblematic upon formation of a picture element part with an ink jetsystem, and a pattern formed of the part having the better wettabilityand the part having the worse wettability can be formed in a few stepsand, further, an ink absorbing layer is not necessary, and which has thebetter quality and which can be produced with the low cost, and aprocess for producing the same.

SUMMARY OF THE INVENTION

In order to attain the aforementioned object, the present inventionprovides a color filter which comprises a transparent substrate, apicture element part in which a plurality of colors are provided in thepredetermined pattern with an ink jet system on the transparentsubstrate, a shading part provided on a border part of the pictureelement part, and a wettability-variable layer being capable of varyingthe wettability which is provided for forming the picture element part,or the picture element part and the shading part.

As described above, the present invention is characterized in that ithas a wettability-variable layer in order to form a picture elementpart, or a picture element part and a shading part. Therefore, byutilizing the change in the wettability of a wettability-variable layer,a picture element part, or a picture element part and a shading part canbe formed with the better precision, and a high quality color filterhaving no problem such as color missing and color nonuniformity can beprovided.

In this case, the construction may be such that at least the pictureelement part is provided on the wettability-variable layer. By forming apicture element part on the wettability-variable layer like this, awettability-variable layer of a part on which a picture element part isformed can be made to be an inkphilic region having a small contactangle with a liquid. By coloring a picture element part forming portionwhich is an inkphilic region with an ink jet system, an ink is adheredto only the picture element part forming portion which is an inkphilicregion having a small contact angle with a liquid, and further an ink isapplied uniformly within the picture element part forming portion whichis an inkphilic region. Therefore, a color having no disadvantage suchas color nonuniformity and color missing can be provided.

In the present invention, when at least the picture element part isprovided on a wettability-variable layer, the following three kinds ofconstructions can be adopted. First is the construction in which theshading part is provided on the transparent substrate, thewettability-variable layer is provided on this shading part and apicture element part forming portion on which the picture element parton the transparent substrate is provided, and further, the pictureelement part is formed on this wettability-variable layer (a colorfilter, in which a picture element part is formed on awettability-variable layer and a wettability-variable layer is providedon a shading part, is referred to as the first embodiment hereinafter).Second is the construction in which a wettability-variable layer isformed on the transparent substrate and a picture element part and ashading part are provided on the predetermined position of thiswettability-variable layer (a color filter, in which a picture elementpart and a shading part are provided on a wettability-variable layer, isreferred to as the second embodiment hereinafter). Third is theconstruction in which the shading part is provided on the transparentsubstrate, a wettability-variable layer is provided on a picture elementpart forming portion on which a picture element part on the transparentsubstrate is formed, and a picture element part is formed on thiswettability-variable layer (a color filter, in which a picture elementpart is formed on a wettability-variable layer and awettability-variable layer is not formed on a shading part, is referredto as the third embodiment hereinafter).

In the aforementioned first embodiment, it is preferable that the widthof the picture element part provided on the wettability-variable layeris wider than the width of an opening formed by the shading part. Thisis because, by forming the width of the picture element part so as to bewider than the width of an opening of a shading part like this, thedisadvantages such as color missing that a backlight passes through apart on which a picture element part is not formed, can be prevented.

In the present invention, it is preferable that an ink-repellent convexpart is formed on a surface of a wettability-variable layer provided onthe shading part. Since by forming an ink-repellent convex part on thesurface of a wettability-variable layer provided on a shading part likethis an ink-repellent convex part is formed between the picture elementpart forming portions upon forming the picture element part by making awettability-variable layer of a picture element part forming portioninto an inkphilic region, the disadvantages such as mixing of inks donot occur, being preferable.

In this case, it is preferable that the width of the ink-repellentconvex part is narrower than that of the shading part. This is becauseby forming the width of an ink-repellent convex part narrower than thatof a shading part like this, the width of a picture element part formedbetween the ink-repellent convex parts can be formed wider than thewidth of an opening formed by a shading part and, thus, theaforementioned effects can be obtained.

On the other hand, in a color filter of the present invention, theconstruction may be such that the wettability-variable layer is providedon a border part of the picture element part. By making the wettabilityof a wettability-variable layer on a border part of a picture elementpart, an ink-repellent region having the larger contact angle with aliquid than that of a part on a transparent substrate on which a pictureelement part is formed like this, since it is difficult for an ink tomigrate over a border part of a picture element part having theink-repellent properties upon coloring a part on which a picture elementpart is provided (picture element part forming portion) with an ink jetsystem, a color filter having no disadvantages such as ink mixing andthe like can be provided. In addition, by making a wettability-variablelayer of a border part of a picture element part an inkphilic regionhaving the small contact angle with a liquid thereafter, providing ofthe shading part on the border part of the picture element part orcovering the whole with a protecting layer can be easily carried outand, thus, a color filter having the high quality can be obtained.

In this case, there are two preferable constructions. One of these isthe construction in which the shading part is formed on the transparentsubstrate, a wettability-variable layer is formed on this shading partand the picture element part is formed between the wettability-variablelayers (a color filter, in which a wettability-variable layer isprovided on a shading part, is referred to as the fourth embodimenthereinafter). Another one is the construction in which thewettability-variable layer is formed on a shading part forming portionwhich is a part on which a shading part on the transparent substrate isformed, the shading part is formed on the wettability-variable layer,and a picture element part is formed between the shading parts (a colorfilter, in which a shading part is formed on a wettability-variablelayer, is referred to as the fifth embodiment hereinafter).

In the fourth embodiment, it is preferable that the width of thewettability-variable layer is formed narrower than that of a shading. Bymaking the width of a wettability-variable layer narrower than that of ashading part, the width of a picture element part formed betweenwettability-variable layers can be formed larger than that of an openingof a shading part. This is because, thereby, the disadvantages such ascolor missing and the like can be prevented.

In the aforementioned third embodiment and a color filter describedabove, in which the wettability-variable layer is provided on a borderpart of the picture element part, it is preferable that the wettabilityon the transparent substrate is less than 10 degrees in terms of thecontact angle with a liquid having the surface tension of 40 mN/m. Thisis because, in the aforementioned third embodiment, an ink for a shadingpart is spread uniformly within a shading part forming portion and itbecomes possible to form a uniform shading part with the betterprecision and, additionally, in the case of a color filter in which awettability-variable layer is provided on a border part of the pictureelement part, since an ink for the picture element part is uniformlyspread with a picture element part forming portion on a transparentsubstrate, the better-quality color filter having no disadvantages suchas color nonuniformity and the like can be provided.

In the present invention, it is preferable that the wettability-variablelayer is a photocatalyst-containing layer comprising at least aphotocatalyst and a binder, and having the wettability which varies sothat the contact angle with a liquid is decreased by irradiation withthe energy. Like this, by forming a photocatalyst-containing layerhaving the wettability which varies so that the contact angle with aliquid is decreased by irradiation with the energy, the wettability ofthis layer can be varied by performing the pattern irradiation of theenergy and the like and an inkphilic region having the small contactangle with a liquid can be formed easily and, for example, it becomespossible to easily make only a part on which a picture element part isformed into an inkphilic region. This is because, therefore, a colorfilter can be manufactured effectively and it becomes advantageous in arespect of cost.

In a color filter described above, it is preferable that thephotocatalyst-containing layer contains fluorine and thephotocatalyst-containing layer is formed so that the content of fluorineon the surface of the photocatalyst-containing layer is decreased by theaction of the photocatalyst as compared with before the irradiation ofthe energy upon irradiating the photocatalyst-containing layer with theenergy.

As mentioned above, since a color filter of the present invention isconstructed such that the fluorine content of the energy irradiated parton a photocatalyst-containing layer formed on a transparent substrate isdecreased, a pattern comprising a part in which the fluorine content isdecreased can be formed by the pattern-irradiation of the energy. Sincewhen the fluorine content is decreased, the part becomes a region havingthe high inkphilicity as compared with other parts, it becomes possibleto easily make only a part on which a picture element part and the likeis formed an inkphilic region, and a color filter can be easilymanufactured.

Further, in a color filter described above, it is preferable that thefluorine content of a part in which the fluorine content is decreased byirradiating the photocatalyst-containing layer with the energy, is 10 orless relative to 100 of the fluorine content of a part which was notirradiated with the energy.

When, like this, the fluorine content of a part having the lowerfluorine content which was formed by irradiating thephotocatalyst-containing layer with the energy, is 10 or less based onthe weight relative to 100 of the fluorine content of a part which isnot irradiated with the energy, a great difference in the inkphilicitybetween a part irradiated with the energy and a part not irradiated withthe energy can be produced. Therefore, by forming a picture element partand the like on a photocatalyst-containing layer on which such thepattern is formed, it becomes possible to precisely form a pictureelement part and the like on only an inkphilic region having the reducedfluorine content and a color filter can be manufactured with the betterprecision.

In the case that a photocatalyst-containing layer used in the presentinvention comprises at least a photocatalyst and a binder as describedabove, it is preferable that the photocatalyst is one or more selectedfrom the group consisting of titanium oxide (TiO₂), zinc oxide (ZnO),tin oxide (SnO₂), strontium titanate (SrTiO₃), tungsten oxide (WO₃),bismuth oxide (Bi₂O₃), and iron oxide (Fe₂O₃). Inter alia, titaniumoxide (TiO₂) is preferable. This is because since titanium oxide has thehigh band gap energy, it is effective as a photocatalyst, is chemicallystable, has no toxicity and is easily available.

In the case of a color filter in which a photocatalyst is titaniumoxide, it is preferable that it has a photocatalyst-containing layer inwhich fluorine element is contained in the surface of thephotocatalyst-containing layer at an amount of 500 or more relative to100 of titanium element as quantified by a X-ray photoelectronspectroscopic method.

This is because, when such the degree of fluorine (F) element iscontained, the ink-repellent properties of a part not irradiated withthe energy are sufficient and, when a pattern of a part having thereduced fluorine (F) element content by the energy irradiation is formedand a picture element part and the like are formed thereon, an ink andthe like do not drop out into a part other than a part on which apicture element part is formed and a color filter can be manufacturedmore precisely.

On the other hand, in a color filter described above, a binder which isthe other component constituting a photocatalyst-containing layer ispreferably organopolysiloxane having a fluoroalkyl group.

The reasons are as follows. In a color filter of the present invention,as a method of inclusion of fluorine element in aphotocatalyst-containing layer, mention may be made of various methods.However, by using organopolysiloxane having a fluoroalkyl group as abinder, fluorine element can be easily contained in aphotocatalyst-containing layer and the content thereof can be easilyreduced by the energy irradiation.

In addition, in a color filter described above, it is preferable that abinder which is the other component constituting aphotocatalyst-containing layer, is formed of organopolysiloxane which isone or more of a hydrolyzed condensed compound or a co-hydrolyzedcondensed compound of a silicon compound represented by Y_(n)SiX_((4−n))(wherein Y represents alkyl group, fluoroalkyl group, vinyl group, aminogroup, phenyl group or epoxy group, X represents alkoxy group orhalogen, and n is an integer of 0 to 3).

In a color filter described above, it is preferable that a siliconcompound having a fluoroalkyl group among the aforementioned siliconcompounds constituting the aforementioned organopolysiloxane iscontained at an amount of not less than 0.01 mol %.

The reasons are as follows. When a silicon compound having a fluoroalkylgroup is contained at an amount of not less than 0.01 mol %, fluorineelement is sufficiently contained in the surface of aphotocatalyst-containing layer and it is possible to make larger thedifference in the wettability between an inkphilic region on aphotocatalyst-containing layer having the reduced fluorine elementcontent resulted from the energy irradiation and an ink-repellent regionon the surface of a photocatalyst-containing layer not irradiated withthe energy. Accordingly, an ink and the like can be precisely attachedinto an ink-repellent region without dropping out upon formation of apicture element part and the like on an inkphilic region, and a colorfilter having the better quality can be manufactured.

In the present invention, it is preferable that the contact angle with aliquid having the surface tension of 40 mN/m on thephotocatalyst-containing layer is 10 degrees or more in a part notirradiated with the energy and the angle is less than 10 degrees in apart irradiated with the energy. Since a part not irradiated with theenergy is a part requiring the ink-repellent properties, when thecontact angle with a liquid having the surface tension of 40 mN/m isless than 10 degrees, the ink-repellent properties are not sufficientand there is a possibility that an ink and a coating material for ashading part and the like remain, being not preferable. On the otherhand, when the contact angle of a part irradiated with the energy with aliquid having the surface tension of 40 mN/m is 10 degrees or more,there is a possibility that the spread of an ink and a coating materialfor a shading part is inferior, color missing and the like may occur ina picture element part.

Further, in the present invention, it is preferable that a pictureelement part colored with the aforementioned ink jet system is a pictureelement part colored with an ink jet system using an UV-curing ink. Thisis because, after a picture element part is colored with an ink jetsystem by using an-UV curing ink, UV is irradiated and, thereby, an inkcan be rapidly cured, which can be sent to a next step, being preferablein a respect of the efficiency.

A liquid crystal panel having the aforementioned color filter and asubstrate opposite thereto and which is obtained by encapsulating aliquid crystal compound between both substrates, has the advantages ofthe aforementioned color filter, that is, the advantages that colormissing and color nonuniformity of a picture element part are notpresent and it is advantageous in a respect of cost.

In the present invention, in order to attain the aforementioned object,there is provided a process for producing a color filter, whichcomprises steps: (1) a step of forming a shading part on a transparentsubstrate, (2) a step of providing a photocatalyst-containing layer inwhich the wettability of a part irradiated with the energy is changed ina direction of the reduction of the contact angle of a liquid, on asurface of the transparent substrate on which a shading part was formed,(3) a step of forming an exposed part for a picture element part byirradiating with the energy a picture element part forming portion whichis a part on this photocatalyst-containing layer on which a pictureelement part is formed, and (4) a step of coloring this exposed part fora picture element part with an ink jet system, to form a picture elementpart (which is referred to as the sixth embodiment hereinafter).

In this embodiment, only a part on which a picture element part isformed can be easily made inkphilic by providing aphotocatalyst-containing layer on a transparent substrate on which ashading part is pre-formed and pattern-irradiating a picture elementpart forming portion with the energy on this photocatalyst-containinglayer. Therefore, a picture element part with an ink uniformly adheredthereto can be obtained by adhering an ink to an exposed part for apicture element part on which this picture element part is to be formedwith an ink jet system and a color filter having neither colornonuniformity nor color missing can be formed.

In the case of the aforementioned sixth embodiment, the embodiment mayhave a step of forming an exposed part for an ink-repellent convex partby pattern-irradiating a photocatalyst-containing layer on a shadingpart with the energy and, whereby, an ink-repellent convex part isformed thereon after a step of provision of the photocatalyst-containinglayer.

Since an exposed part for an ink-repellent convex part is provided alsoon a photocatalyst-containing layer on a shading part by the patternirradiation of the energy, an exposed part for an ink-repellent convexpart having the predetermined width can be formed. Therefore, theink-repellent convex part having the predetermined width can be obtainedat a uniform height by applying a coating material for an ink-repellentconvex part on this region.

Further, in the sixth embodiment of the present invention, an exposedpart for a picture element part may be formed by exposing from thetransparent substrate side using the shading part as a mask in a step offorming the aforementioned exposed part for a picture element part. Bywhole surface-exposing from the transparent substrate side, that is, aside on which a shading part is not formed, only aphotocatalyst-containing layer corresponding to a part formed on theupper side of a shading part is not exposed and the other part can beexposed. Therefore, since the energy pattern irradiation can beperformed without using a photomask and the like, it is advantageous ina respect of cost.

In addition, the present invention provides a process for production ofa color filter, which comprises steps: (1) a step of providing aphotocatalyst-containing layer having the wettability of theenergy-irradiated part which changes in a direction of reduction of thecontact angle with a liquid, on a transparent substrate, (2) a step offorming an exposed part for a shading part on a shading part formingportion on the transparent substrate on which a shading part is to beformed by pattern-irradiating with the energy, (3) a step of providing ashading part on this exposed part for a shading part, (4) a step offorming an exposed part for a picture element part on a transparentsubstrate on which this shading part is formed by the energyirradiation, and (5) a step of coloring this exposed part for a pictureelement part with an ink jet system, to form a picture element part(hereinafter referred to as the seventh embodiment).

In a process for producing a color filter in this embodiment, byproviding a photocatalyst-containing layer on a transparent substrateand irradiating this photocatalyst-containing layer with the energy, thecontact angle with a liquid of an exposed part can be reduced.Therefore, only a region forming a shading part can be first made to bean inkphilic region by simply pattern-irradiating aphotocatalyst-containing layer with the energy upon formation of ashading part and, then, a shading part can be formed by applying acoating material for a shading part on this part. Therefore, since adeveloping step and an etching step after pattern-exposure which havebeen previously performed upon provision of a shading part need not tobe performed. Accordingly, a shading part can be formed effectively. Inaddition, thereafter, a region forming a picture element part can beeasily made to be an inkphilic region, for example, by irradiating thewhole surface with the energy. Therefore, when the region is coloredwith an ink jet system, a picture element part with an ink uniformlyadhered thereto can be obtained and a color filter having neither colormissing nor color nonuniformity can be formed.

In addition, the present invention provides a process for producing acolor filter, which comprises steps: (1) a step of providing aphotocatalyst-containing layer having the wettability of theenergy-irradiated part which changes in a direction of reduction of thecontact angle with a liquid, on a transparent substrate, (2) a step offorming an exposed part for a picture element part on a picture elementpart forming portion which is a part on the transparent substrate, onwhich a picture element part is to be formed by pattern-irradiating withthe energy, (3) a step of coloring this exposed part for a pictureelement part with an ink jet system, to form a picture element part, (4)a step of irradiating a photocatalyst-containing layer on at least aborder part of the picture element part with the energy, and (5) a stepof forming a shading part on the border part of a picture element partirradiated with the energy (hereinafter referred to as the eighthembodiment).

In this case, a photocatalyst-containing layer is formed on a pictureelement part forming portion which is a part on a transparent substrateon which at least a picture element part is to be formed, and on ashading part forming portion which is a part on which a shading part isto be formed. And a picture element part forming portion of thisphotocatalyst-containing layer can be first made to be an inkphilicregion by pattern-irradiating the picture element part forming portionwith the energy. Therefore, by adhering an ink thereto with an ink jetsystem, an ink is uniformly spread and color nonuniformity and the likedo not occur. In addition, a shading part forming portion which is aborder part between the picture element parts is not irradiated with theenergy and, thus, it remains an ink-repellent region. Therefore, it canbe said that it is difficult for an ink adhered to a picture elementpart forming portion which is an inkphilic region to migrate over ashading part forming portion which is an ink-repellent region.Accordingly, a problem such as the ink mixing does not occur. Byirradiating a shading part forming portion between the picture elementparts after a picture element part is formed, this part can be made intoan inkphilic region. Therefore, by applying this part, for example, withan ink for a shading part, a shading part can be easily formed.

Further, the present invention provides a process for producing colorfilter, which comprises steps: (1) a step of providing aphotocatalyst-containing layer having the wettability of theenergy-irradiated part which changes in a direction of reduction of thecontact angle with a liquid on a transparent substrate, on a pictureelement part forming portion on the transparent substrate which is apart on which a picture element part is to be formed, (2) a step ofproviding a shading part on a border part of the picture element partforming portion on which the photocatalyst-containing layer is provided,(3) a step of forming an exposed part for a picture element part byirradiating the photocatalyst-containing layer with the energy, and (4)a step of coloring this exposed part for a picture element part with anink jet system to form a picture element part (hereinafter referred toas the ninth embodiment).

In this case, a photocatalyst-containing layer is first formed on apicture element part forming portion which is a part on a transparentsubstrate on which a picture element part is to be formed. When amaterial having the higher contact angle with a liquid than thetransparent substrate surface in the state before the energyirradiation, is used in this photocatalyst-containing layer, a shadingpart forming portion on a substrate between the picture element partforming portions becomes an inkphilic region having the smaller contactangle with a liquid rather than a picture element part forming portionon which this photocatalyst-containing layer is formed. For example, byforming a shading part on this inkphilic region with a coating materialfor a shading part, a shading part can be first formed easily. Then, forexample, by irradiating the whole surface on which this shading part isformed with the energy, a picture element part forming portion can bemade into an inkphilic region. Therefore, by coloring this region withan ink jet system, a picture element part with an ink uniformly adheredthereto is obtained and a color filter having neither color missing norcolor nonuniformity can be formed.

In addition, in the present invention, there is provided a process forproducing a color filter, which comprises steps: (1) a step of forming ashading part on a transparent substrate, (2) a step of providing aphotocatalyst-containing layer having the wettability of theenergy-irradiated part which changes in a direction of reduction of thecontact angle with a liquid on this shading part, and (3) a step ofcoloring with an ink jet system a picture element part forming portionwhich is a part on a transparent substrate with nophotocatalyst-containing layer provided on which a picture element partis to be formed, to form a picture element part (hereinafter referred toas the tenth embodiment).

In this case, a shading part is first formed on a transparent substrateand a photocatalyst-containing layer is formed thereon. When a materialhaving the higher contact angle with a liquid than the transparentsubstrate surface at the state before the energy irradiation is used inthis photocatalyst-containing layer, a picture element part formingportion between photocatalyst-containing layers becomes an inkphilicregion having the smaller contact angle with a liquid rather than thisphotocatalyst-containing layer and a photocatalyst-containing layerwhich is a border part of a picture element part forming portion is madeinto an ink-repellent region. Therefore, when an ink is adhered to apicture element part forming portion which is an inkphilic region withan ink jet system, it is difficult for an adhered ink to migrate over ashading part forming portion which is an ink-repellent region. Hence, aproblem such as the ink mixing hardly occurs.

Further, in the present invention, there is provided a process forproducing a color filter, which comprises steps: (1) a step of providinga photocatalyst-containing layer having the wettability of theenergy-irradiated part which changes in a direction of reduction of thecontact angle with a liquid on a transparent substrate, on a shadingpart forming portion which is a part on a transparent substrate on whicha shading part is to be formed, (2) a step of coloring with an ink jetsystem a part on the transparent substrate on which aphotocatalyst-containing layer is not formed to form a picture elementpart, (3) a step of irradiating at least the photocatalyst-containinglayer with the energy, and (4) a step of forming a shading part on thephotocatalyst-containing layer irradiated with the energy (hereinafterreferred to as the eleventh embodiment).

In this case, a photocatalyst-containing layer is provided on a shadingpart forming portion on a transparent substrate on which a shading partis to be formed. When a material having the higher contact angle with aliquid in the state before the energy irradiation than the transparentsubstrate surface is used in this photocatalyst-containing layer, apicture element part forming portion between shading part formingportions becomes into an inkphilic region having the smaller contactangle with a liquid rather than a shading part forming portion on whichthis photocatalyst-containing layer is formed, and a shading partforming portion which is a border part between the picture element partforming portions becomes into an ink-repellent region. Therefore, whenan ink is adhered with an ink jet system to a picture element partforming portion which is an inkphilic region, an adhered ink does notmigrate over a shading part forming portion which is an ink-repellentregion. Hence, a problem such as the ink mixing does not occur. After apicture element part is formed in such as way, by irradiating aphotocatalyst-containing layer of a shading part forming portion betweenpicture element parts with the energy, this part can be converted intoan inkphilic region. Therefore, for example, by applying this part withan ink for a shading part, a shading part can be formed easily.

Further, in addition, in the aforementioned sixth embodiment and eightembodiment, a step of forming the exposed part for a picture elementpart and, thereafter, forming a picture element part by coloring thepart with an ink jet system may comprise (a) a step of forming anexposed part for the first picture element part by pattern-irradiating aportion of a part on the photocatalyst-containing layer on which apicture element part is to be formed with the energy, (b) a step ofcoloring the exposed part for the first picture element part with an inkjet system to form the first picture element part, (c) a step ofexposing a part forming the remainder picture element part on thephotocatalyst-containing layer to form an exposed part for the secondpicture element part, and (d) a step of coloring this exposed part forthe second picture element part with an ink jet system to form thesecond picture element part.

That is, in any embodiment, a picture element part is formed by formingan exposed part for a picture element part and coloring this part withan ink jet system. And upon formation of the picture element part,picture element parts are divided into the first picture element partand the second picture element part, which are colored with the energyirradiation and an ink jet system, respectively.

When a picture element part is formed by coloring with an ink jet systeman exposed part for a picture element part which was converted into aninkphilic region by the energy irradiation, if the distance between theexposed parts for a picture element part is narrow, there may occur apossibility that inks of neighboring picture element parts are mixedover an ink-repellent region between picture element parts uponformation of a picture element part. Therefore, it is desirable thatpicture element parts are formed in the mutually isolated state uponformation of a picture element part. As described above, when a methodof first forming the first picture element part and, thereafter, formingthe second picture element part is adopted, for example, the patternexposure can be performed so that picture element parts are formedalternately upon preparing the first picture element part and theneighboring picture element parts can be in the mutually isolated stateupon the first time formation of a picture element part. By forming anexposed part for the first picture element part in the state where arelatively wide ink-repellent region is retained between regions to becolored, which is colored with an ink jet system, a possibility iseliminated that the disadvantages that inks of the neighboring pictureelement parts are mixed, occur. By irradiating again between the firstpicture element parts thus provided with the energy to form an exposedpart for the second picture element part, which is colored with an inkjet system, a color filter can be formed which has no disadvantages suchas the ink mixing and the like.

In addition, in the sixth embodiment and the tenth embodiment of thepresent invention, it is preferable that the width of the pictureelement part is formed wider than that of an opening formed by theshading part. This is because, by making the width of a picture elementpart wider than that of an opening formed by a shading part like this, apossibility that the backlight passes through parts other than pictureelement parts can be made smaller and color missing and the like can beprevented.

Further, in the ninth embodiment, the tenth embodiment and the eleventhembodiment of the present invention, it is preferable that thewettability on the transparent substrate is less than 10 degrees as acontact angle with a liquid having the surface tension of 40 mN/m. Ineither embodiment, after a photocatalyst-containing layer having theink-repellent properties as compared with a transparent substrate isformed, a picture element part or a shading part is provided on a parton which a photocatalyst-containing layer is not formed. And when thewettability of the surface of the transparent substrate is less than 10degrees as a contact angle with a liquid having the surface tension of40 mN/m, a liquid is easily spread and, for example, in the case of apicture element part, since an ink for an ink jet is uniformly spread, apicture element part having no color nonuniformity is obtained and,thus, a color filter having the high quality can be obtained.

In the present invention, the energy for exposure by irradiation to aphotocatalyst-containing layer is usually the light including theultraviolet ray. However, when formation of the pattern by lightpicturing irradiation is performed, an exposed part may be formed usingas this energy the photocatalystic reaction initiation energy and thereaction rate increasing energy, and irradiating with the reaction rateincreasing energy a part irradiated with the photocatalystic reactioninitiation energy.

This is to form the pattern of an exposed part by adding thephotocatalystic reaction initiation energy to a photocatalyst-containinglayer and adding the reaction rate increasing energy by patterning to aregion which received this photocatalystic reaction initiation energy.That is, since the formation of the pattern by light picturingirradiation proposed hitherto by the present inventors used thephotocatalystic reaction irradiation energy such as the ultraviolet ray,there was problems that the apparatus is expensive, the handling wasdifficult, the continuous output was not possible, and the like.However, in this method, since the photocatalystic reaction initiationenergy such as the ultraviolet ray is added and the pattern is formedusing the reaction rate increasing energy such as the infrared rayrelative to a region which received the photocatalystic reactioninitiation energy, there is the advantages that the reaction rateincreasing energy such as the infrared laser which is relatively lowcost and is easily handled can be used upon formation of the pattern.

In the present invention, when two kinds of energies of thephotocatalystic reaction initiation energy and the reaction rateincreasing energy are used, it is preferable that the photocatalysticreaction initiation energy is the light including the ultraviolet rayand the reaction rate increasing energy is the heat energy. This isbecause titanium dioxide is suitably used as a photocatalyst in thepresent invention, therefore the ultraviolet ray is preferable as thephotocatalystic reaction initiation energy from the relationship of theband gap of this titanium dioxide. In addition, although it ispreferable that the reaction rate increasing energy is the heat, it ispreferable that the heat energy is added by the infrared laser. This isbecause a method of using the infrared laser is relatively low coat andis easily handled.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic sectional view showing an example of the firstembodiment of the color filter according to the present invention.

FIG. 2 is a schematic sectional view showing an another example of thefirst embodiment of the color filter according to the present invention.

FIG. 3 is a schematic sectional view showing one example of the secondembodiment of the color filter according to the present invention.

FIG. 4 is a schematic sectional view showing one example of the thirdembodiment of the color filter according to the present invention.

FIG. 5 is a schematic sectional view showing one example of the fourthembodiment of the color filter according to the present invention.

FIG. 6 is a schematic sectional view showing one example of the fifthembodiment of the color filter according to the present invention.

FIG. 7 is a process drawing for explaining the sixth embodiment of aprocess for producing the color filter according to the presentinvention.

FIG. 8 is a schematic view for explaining an another example of exposingmethod for a picture element part in the process for producing a colorfilter shown in FIG. 7.

FIG. 9 is a process drawing for explaining a process for producing anink-repellent convex part in the process for producing a color filtershown in FIG. 7.

FIG. 10 is a process drawing for explaining an another example of aproduction of a picture element part in the process for producing acolor filter shown in FIG. 7.

FIG. 11 is a process drawing for explaining the seventh embodiment ofthe process for producing a color filter according to the presentinvention.

FIG. 12 is a process drawing for explaining the eighth embodiment of theprocess for producing a color filter according to the present invention.

FIG. 13 is a process drawing for explaining the tenth embodiment of theprocess for producing a color filter according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be explained in detail and a color filter isfirst explained and, then, a process for producing a color filter isexplained.

A. Color Filter

First, the color filter according to the present invention is explained.The color filter according to the present invention comprises atransparent substrate, a picture element part in which a plurality ofcolors are provided in the predetermined pattern with an ink jet systemon the transparent substrate, a shading part provided on a border partof the picture element part, and a wettability-variable layer beingcapable of varying the wettability which is provided for forming thepicture element part, or the picture element part and the shading part.

The present invention has a wettability-variable layer in order to forma picture element part as described above, or a picture element part anda shading part. Therefore, since a picture element part or a pictureelement part and a shading part can be easily formed by varying thewettability of a wettability-variable layer, a color filter having thehigh quality can be obtained at the low cost. “In order to form apicture element part or a picture element part and a shading part”herein includes the meaning that a picture element part, or a pictureelement part and a shading part are positioned on a transparentsubstrate.

As the specific positional relationship of each element of such thecolor filter, for example, mention may be made of the relationship thatat least the picture element part is provided on thewettability-variable layer.

Since at least a picture element part is provided on awettability-variable layer like this, the wettability of a part on whicha picture element part is to be provided in advance can be made into aninkphilic region having the small contact angle with a liquid and theother part can be made into an ink-repellent region having the largecontact angle with a liquid. Since an ink is adhered to only aninkphilic region having the small contact angle with a liquid bycoloring this part on which a picture element part is to be providedwith an inkjet system, an ink is uniformly spread over the whole pictureelement part, a region having no ink is not present and colornonuniformity and the like do not occur in a picture element part, andan ink is not adhered to the other ink-repellent region.

In addition, as an another specific positional relationship of eachelement in the color filter according to the present invention, forexample, mention may be made of an example in which awettability-variable layer is formed on a border part of a pictureelement part. In this case, since an ink is difficult to migrate over aborder part of a picture element part having the ink-repellentproperties upon coloring with an ink jet system a part on which apicture element part is to be provided by making the wettability of aborder part of a picture element part into that of an ink-repellentregion having the worse wettability than that of a part on which apicture element part is to be provided, a color filter having nodisadvantages such as the ink mixing can be provided. In addition,thereafter, by making a wettability-variable layer of a border part of apicture element part into an inkphilic region having the small contactangle with a liquid by adding the stimulation and the like, a shadingpart can be easily provided on this border part of the picture elementpart border and the whole can be easily covered with a protecting layerand, thus, a color filter having the high quality can be obtained.

The color filter according to the present invention, having such thewettability-variable layer is explained in detail below by means of someembodiments.

The First Embodiment

The first embodiment of the present invention is a color filter in whicha shading part is formed on a transparent substrate, awettability-variable layer is provided on a picture element part formingportion which is a part on at least this shading part and on thetransparent substrate on which the picture element part is to be formed,and further a picture element part can be formed with the betterprecision by varying the wettability on this wettability-variable layer.This shows an example in which a wettability-variable layer is providedfor forming a picture element part and is one of specific examples of acolor filter in which the aforementioned at least a picture element partis provided on a wettability-variable layer.

FIG. 1 shows one example of the first embodiment. This color filter 1has a shading part 3 provided on a transparent substrate 2, awettability-variable layer 5 provided on a picture element part formingportion 4 which is a part on the shading part 3 and on the transparentsubstrate 2, on which a picture element part is to be formed, and apicture element part 6 formed on a picture element part forming portion4 on this wettability-variable layer 5. A picture element part formingportion 4 shows a horizontal-directional position on the surface of atransparent substrate 2 on which a picture element part 6 is to beformed, and may be on a transparent substrate 2 or on awettability-variable layer 5. In addition, a shading part 3 is alsodesignated as a black matrix and is usually formed on a border part of apicture element part 6.

In a color filter of the first embodiment, a picture element partforming portion 4 on a wettability-variable layer can be converted intoan inkphilic region by pattern-irradiating a picture element partforming portion 4 on a wettability-variable layer 5 with the energy.Therefore, by coloring this region with an ink by an ink jet system, theuniform and high quality color filter having no color nonuniformity canbe obtained.

In the first embodiment of the present invention, it is preferable thatthe width of a picture element part 6 is formed wider than that of anopening formed by a shading part 3. By adopting such the constructions,upon mounting this color filter and irradiating with the backlight, thebacklight does not pass through a part on which a picture element partis not formed and the high quality color filter having no color missingcan be obtained.

FIG. 2 shows an another example of the first embodiment. In thisexample, an ink-repellent convex part 7 is formed on awettability-variable layer 5 on a shading part 3. Since an ink-repellentconvex part 7 is formed in a color filter 1 of this example like this,an ink is not flown out over this ink-repellent convex part 7 uponadhering an ink to a picture element part forming portion 4 with an inkjet system and, thus, a color filter having a picture element part whichdoes not mix with an ink of an another color can be obtained. In thiscase, the width of the ink-repellent convex part 7 is not particularlylimited but preferably narrower than that of a shading part 3 as shownin FIG. 2. By adopting such the construction, when a picture elementpart 6 is formed, the width of a picture element part 6 can be widerthan that of an opening of a shading part 3, and the aforementionedeffects can be obtained. Hence, the high quality color filter having nocolor missing can be obtained.

Each part constituting such the color filter is explained below.

(Wettability-variable Layer)

The wettability-variable layer is not particularly limited so long asthe wettability of the surface thereof can be varied by the externalstimulation, for example, physical stimulation and chemical stimulation.For example, the layer may be a layer in which the state of roughness ofthe surface is varied by an acid, an alkali and the like and, whereby,the wettability is varied, or a layer in which a substance in thewettability-variable layer is changed by irradiation of the energy suchas the ultraviolet light, the visible light and the heat and, whereby,the wettability is changed.

In addition, regarding the change in the wettability, the layer may be awettability-variable layer in which a contact angle with a liquid isgreat before the addition of stimulation and a contact angle with aliquid is changed so that it becomes smaller after the addition ofstimulation, or a wettability-variable layer in which a contact anglewith a liquid is conversely small before the addition of stimulation anda contact angle with a liquid is greatly changed.

(Photocatalyst-containing Layer)

In the present invention, it is preferable that thiswettability-variable layer is a photocatalyst-containing layer in whichthe wettability changes so that a contact angle with a liquid is reducedby the energy irradiation. The reasons are as follows. By providing aphotocatalyst-containing layer in which the wettability changes so thata contact angle with a liquid is reduced by exposure (which means notonly the light irradiation but also the energy irradiation in thepresent invention) like this, the photocatalyst-containing layer can bemade into an inkphilic region having the small contact angle with aliquid by pattern-irradiating with the energy to easily change thewettability and, for example, only a part on which a picture elementpart is to be formed can be easily made into an inkphilic region.Therefore, a color filter can be manufactured effectively and it becomesadvantageous in a respect of cost. In this case, it is preferable thatthe light including the ultraviolet ray is used as the energy.

An inkphilic region herein is a region having the small contact anglewith a liquid and is intended to refer to a region having the betterwettability relative to an ink for an ink jet, a coating material for ashading part and the like. In addition, an ink-repellent region is aregion having the great contact angle with a liquid and is intended torefer to a region having the worse wettability relative to an ink for anink jet, a coating material for a shading part and the like.

It is preferable that, in the photocatalyst-containing layer, a contactangle with a liquid having the surface tension of 40 mN/m is 10 degreesor more in a part not exposed, preferably a contact angle with a liquidhaving the surface tension of 30 mN/m is 10 degrees or more and,particularly, a contact angle with a liquid having the surface tensionof 20 mN/m is 10 degrees or more. This is because, since a part notexposed is required to be ink-repellent in the present invention, when acontact angle with a liquid is small, the ink-repellent properties arenot sufficient and there arises a possibility that an ink or a coatingmaterial for a shading part remains, being not preferable.

In addition, it is preferable that the photocatalyst-containing layer isa layer in which a contact angle with a liquid is reduced when exposedand a contact angle with a liquid having the surface tension of 40 mN/mbecomes less than 10 degrees, preferably a contact angle with a liquidhaving the surface tension of 50 mN/m becomes 10 degrees or less and,particularly, a contact angle with a liquid having the surface tensionof 60 mN/m becomes 10 degrees or less. When a contact angle with aliquid of an exposed part is high, there is a possibility that thespread of an ink or a coating material for a shading part in this partis inferior and color missing or the like occurs in a picture elementpart.

A contact angle with a liquid herein is obtained from the results bymeasuring a contact angle with liquids having various surface tensionsusing a contact angle measuring apparatus (type CA-Z manufactured byKyowa Interface science Co., Ltd.) (after 30 seconds from dropping adroplet from a microsyringe) or making a graph from the results. Inaddition, as liquids having various surface tensions upon thismeasurement, the wettability index standard solutions manufactured byJunsei Science Co., Ltd. can be used.

It is preferable that a photocatalyst-containing layer in the presentinvention comprises at least a photocatalyst and a binder. By adoptingsuch the layer, it becomes possible to make the critical surface tensionhigher by the action of the energy irradiation and a contact angle witha liquid can be reduced.

Although the action mechanism of a photocatalyst representing titaniumoxide described below in such the photocatalyst-containing layer is notnecessarily clear, it is considered that a carrier produced by the lightirradiation has influences on the chemical structure of organicsubstances by the direct reaction with an adjacent compound or activeoxygen species in the presence of oxygen and water.

When a photocatalyst-containing layer is used as a wettability-variablelayer in the present invention, the layer can be made into inkphilic bychanging the wettability of an exposed part using the action ofoxidation, degradation and the like of an organic group which is aportion of a binder or additives with a photocatalyst and, whereby,there can be arisen the great difference in the wettability between anexposed part and an unexposed part. Hence, by enhancing theacceptability (inkphilicity) and the repellent properties (ink-repellentproperties) with a coating material for a shading part or an ink of anink jet system, a color filter having the better quality and which isalso advantageous in a respect of cost can be obtained.

In addition, when such the photocatalyst-containing layer is used in thepresent invention, the photocatalyst-containing layer may be formed suchthat it contains at least a photocatalyst and fluorine and further thecontent of fluorine in the surface of this photocatalyst-containinglayer is reduced with the aforementioned action of a photocatalyst ascompared with before the energy irradiation upon irradiating thephotocatalyst-containing layer with the energy.

In a color filter having such the characteristics, a pattern comprisinga part having the small content of fluorine can be easily formed bypattern-irradiating with the energy. Here, fluorine has the extremelylow surface energy and, for this reason, the surface of a substancehaving a large amount of fluorine becomes smaller in the criticalsurface tension. Therefore, the critical surface tension of a partcontaining a small amount of fluorine becomes greater as compared withthe critical surface tension of the surface of a part containing a greatamount of fluorine. This means that a part containing a small amount offluorine becomes an inkphilic region as compared with a part containinga great amount of fluorine. Hence, the formation of a pattern comprisinga part having a small amount of fluorine as compared with thesurrounding surface results in the formation of an inkphilic regionpattern in an ink-repellent region.

Therefore, when such the photocatalyst-containing layer is used, sincethe pattern of an inkphilic region can be easily formed within anink-repellent region by pattern-irradiation of the energy, it becomespossible to easily form a picture element part and the like in only thisinkphilic region and a color filter having the better quality can beobtained.

It is preferable that, regarding the content of fluorine contained in aphotocatalyst-containing layer containing fluorine as described above,the content of fluorine in an inkphilic region having the lower contentof fluorine which was formed by the energy irradiation is 10 or less,preferably 5 or less, particularly preferably 1 or less when thefluorine content in a part not irradiated with the energy is 100.

The reasons are as follows. By selecting the fluorine content in suchthe range, it is possible to produce the great difference in theinkphilic properties between the energy-irradiated part and theenergy-unirradiated part. Therefore, by forming a picture element partand the like on such the photocatalyst-containing layer, it becomespossible to precisely form a picture element part and the like in onlyan inkphilic region having the reduced fluorine content and a colorfilter can be obtained with the better precision. This rate of reductionis based on weight.

Various methods which are generally performed can be used to measure thefluorine content in such the photocatalyst-containing layer and, forexample, a method which can quantitatively measure the fluorine amountin the surface such as X-ray Photoelectron Spectroscopy, also called asESCA (Electron Spectroscopy for Chemical Analysis), fluorescent X-rayanalysis, and mass spectroscopy can be used, being not limiting.

As a photocatalyst used in the present invention, mention may be made ofphotosemiconductors such as titanium oxide (TiO₂), zinc oxide (ZnO), tinoxide (SnO₂), strontium titanate (SrTiO₃), tungten oxide (WO₃), bismuthoxide (Bi₂O₃), and iron oxide (Fe₂O₃). One or more may be selected fromthem and mixed for use.

In the present invention, particularly, titanium oxide is suitably usedbecause titanium oxide has the high band gap energy, is chemicallystable and not toxic, and can be obtained easily. There are two types oftitanium oxide, anatase and rutile. Although both can be used in thepresent invention, anatase-type titanium oxide is preferable.Anatase-type titanium oxide has the excitation wavelength of not greaterthan 380 nm.

As such the anatase-type titanium oxide, mention may be made ofhydrochloric acid-defloccuated-type anatase-type titania sol (STS-02(average particle size 7 nm) manufactured by Ishihara Sangyo Kaisha,LTD., ST-K01 manufactured by Ishihara Sangyo Kaisha, LTD.), and nitricacid-defloccuated-type anatase-type titania sol (TA-15 (average particlesize 12 nm) manufactured by Nissan Chemical Industries, Ltd.).

The small particle size of a photocatalyst is preferable because thephotocatalystic reaction occurs effectively. The average particle sizeof 50 nm or less is preferable and it is particularly preferable to usea photocatalyst having the average particle size of not greater than 20nm. As the particle size of a photocatalyst is smaller, the surfaceroughness of a photocatalyst-containing layer becomes smaller, beingpreferable. When the particle size of a photocatalyst exceeds 100 nm,the central line average surface roughness becomes larger, theink-repellent properties of an unexposed part of aphotocatalyst-containing layer are reduced and manifestation of theinkphilic properties of an exposed part becomes insufficient, being notpreferable.

The color filter of the present invention may be a color filter obtainedby incorporating fluorine in the surface of a photocatalyst-containinglayer as described above, reducing the fluorine content in the surfaceof a photocatalyst-containing layer by pattern-irradiating the surfaceof this photocatalyst-containing layer with the energy and, thereby,forming the pattern of an inkphilic region in an ink-repellent regionand forming a picture element part and the like thereon. Even in thiscase, titanium oxide is preferably used as a photocatalyst. The contentof fluorine contained in a photocatalyst-containing layer when titaniumoxide is used like this, is preferable such that fluorine (F) element iscontained in the surface of a photocatalyst-containing layer at anamount of not less than 50, preferably not less than 800, particularlypreferably 1200 relative to 100 of titanium (Ti) element asquantitatively determined by analyzing by X-ray photoelectronspectroscopy.

The reasons are as follows. Since it becomes possible to sufficientlyreduce the critical surface tension in a photocatalyst-containing layerby inclusion of such a degree of fluorine (F) in aphotocatalyst-containing layer, the ink-repellent properties in thesurface can be retained and, thereby, the difference in the wettabilitybetween the ink-repellent region and an inkphilic region in the surfacein the pattern part having the reduced fluorine content by thepattern-irradiation of the energy and the quality of the finallyobtained color filter can be improved.

Further, in such the color filter, it is preferable that the fluorinecontent in an inkphilic region formed by the pattern irradiation of theenergy is such that fluorine (F) element is contained at a rate of notgreater than 50, preferably not greater than 20, particularly preferablynot greater than 10 relative to 100 loo of titanium (Ti) element.

When the fluorine content in a photocatalyst-containing layer can bereduced to such the degree, the sufficient inkphilic properties can beobtained in order to form a picture element part and the like, itbecomes possible to form a picture element part and the like with thebetter precision due to the difference in the wettability between theinkphilic region and the ink-repellent region not irradiated with theenergy, and a color filter having the better quality can be obtained.

In the present invention, it is preferable that a binder used in aphotocatalyst-containing layer has such the high binding energy that theprincipal chain is not degraded by the photoexcitation of theaforementioned photocatalyst, for example, mention may be made of (1)organopolysiloxane which exerts the great strength and which is obtainedby hydrolyzing and polymerization-condensing chloro or alkoxysilane by asol-gel reaction or the like, and (2) organopolysiloxane obtained bycross-linking reactive silicone having the excellent water-repellencyand oil-repellency.

In the case of the aforementioned (1), organopolysiloxane which isobtained by hydrolyzing and condensing or co-hydrolyzing and condensingone or more of silicon compounds represented by the general formula:

Y_(n)SiX_((4−n))

(wherein Y represents alkyl group, fluoroalkyl group, vinyl group, aminogroup, phenyl group or epoxy group, X represents alkoxyl group, acetylgroup or halogen, and n is an integer of 0 to 3). A number of carbon ofa group denoted by Y is preferably in a range of 1 to 20 and alkoxylgroup denoted by X is preferably methoxy group, ethoxy group, propoxygroup, and butoxy group.

More particularly, there can be used methyltrichlorsilane,methyltribromsilane, methyltrimethoxysilane, methyltriethoxysilane,methyltriisopropoxysilane, methyltri-t-butoxysilane;ethyltrichlorsilane, ethyltribromsilane, ethyltrimethoxysilane,ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltri-t-butoxysilane;n-propyltrichlorsilane, n-propyltribromsilane, n-propyltrimethoxysilane,n-propyltriethoxysilane, n-propyltriisopropoxysilane,n-propyltri-t-butoxysilane; n-hexyltrichlorsilane, n-hexyltribromsilane,n-hexyltrimethoxysilane, n-hexyltriethoxysilane,n-hexyltriisopropoxysilane, n-hexyltri-t-butoxysilane;n-decyltrichlorsilane, n-decyltribromsilane, n-decyltrimethoxysilane,n-decyltriethoxysilane, n-decyltriisopropoxysilane,n-decyltri-t-butoxysilane; n-octadecyltrichlorsilane,n-octadecyltribromsilane, n-octadecyltrimethoxysilane,n-octadecyltriethoxysilane, n-octadecyltriisopropoxysilane,n-octadecyltri-t-butoxysilane; phenyltrichlorsilane,phenyltribromsilane, phenyltrimethoxysilane, phenyltriethoxysilane,phenyltriisopropoxysilane, phenyltri-t-butoxysilane, tetrachlorsilane,tetrabromsilane, tetramethoxysilane, tertaethoxysilane,tetrabutoxysilane, dimethoxydiethoxysilane; dimethyldichlorsilane,dimethyldibromsilane, dimethyldimethoxysilane, dimethyldiethoxysilane;diphenyldichlorsilane, diphenyldibromsilane, diphenyldimethoxysilane,diphenyldiethoxysilane; phenylmethyldichlorsilane,phenylmethyldibromsilane, phenylmethyldimethoxysilane,phenylmethyldiethoxysilane; trichlorhydrosilane, tribromhydrosilane,trimethoxyhyrosilane, triethoxyhydrosilane, triisopropoxyhydrosilane,tri-t-butoxyhydrosilane; vinyltrichlorsilane, vinyltribromsilane,vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane,vinyltri-t-butoxysilane; trifluoropropyltrichlorsilane,trifluoropropyltribromsilane, trifluoropropyltrimethoxysilane,trifluoropropyltriethoxysilane, trifluoropropyltriisopropoxysilane,trifluoropropyltri-t-butoxysilane;γ-glycidoxypropylmethyldimethoxysilane,γ-glycidoxypropylmethyldiethoxysilane,γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane,γ-glycidoxypropyltriisopropoxysilane,γ-glycidoxypropyltri-t-butoxysilane;γ-methacryloxypropylmethyldimethoxysilane,γ-methacryloxypropylmethyldiethoxysilane,γ-methacryloxypropyltrimethoxysilane,γ-methacryloxypropyltriethoxysilane,γ-methacryloxypropyltriisopropoxysilane,γ-methacryloxypropyltri-t-butoxysilane;γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane,γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane,γ-aminopropyltriisopropoxysilane, γ-aminopropyltri-t-butoxysilane;γ-mercaptopropylmethyldimethoxysilane,γ-mercaptopropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane,γ-mercaptopropyltriethoxysilane, γ-mercaptopropyltriisopropoxysilane,γ-mercaptopropyltri-t-butoxysilane;β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,β-(3,4-epoxycyclohexyl)ethyltriethoxysilane; and partial hydrolysatethereof; and mixture thereof.

In addition, as a binder, particularly, polysiloxane containingfluoroalkyl group can be preferably used. More particularly, mention maybe made of hydrolyzed and condensed compound and cohydrolyzed andcondensed compound of one or more of the following fluoroalkylsilanes.Generally, the known fluorine-contained silane coupling agents can beused.

CF₃(CF₂)₃CH₂CH₂Si(OCH₃)₃;

CF₃(CF₂)₅CH₂CH₂Si(OCH₃)₃;

CF₃(CF₂)₇CH₂CH₂Si(OCH₃)₃;

CF₃(CF₂)₉CH₂CH₂Si(OCH₃)₃;

(CF₃)₂CF(CF₂)₄CH₂CH₂Si(OCH₃)₃;

(CF₃)₂CF(CF₂)₆CH₂CH₂Si(OCH₃)₃;

(CF₃)₂CF(CF₂)₈CH₂CH₂Si(OCH₃)₃;

CF₃(C₆H₄)C₂H₄Si(OCH₃)₃;

CF₃(CF₂)₃(C₆H₄)C₂H₄Si(OCH₃)₃;

CF₃(CF₂)₅(C₆H₄)C₂H₄Si(OCH₃)₃;

CF₃(CF₂)₇(C₆H₄)C₂H₄Si(OCH₃)₃;

CF₃(CF₂)₃CH₂CH₂SiCH₃(OCH₃)₂;

CF₃(CF₂)₅CH₂CH₂SiCH₃(OCH₃)₂;

CF₃(CF₂)₇CH₂CH₂SiCH₃(OCH₃)₂;

CF₃(CF₂)₉CH₂CH₂SiCH₃(OCH₃)₂;

(CF₃)₂CF(CF₂)₄CH₂CH₂SiCH₃(OCH₃)₂;

(CF₃)₂CF(CF₂)₆CH₂CH₂SiCH₃(OCH₃)₂;

(CF₃)₂CF(CF₂)₈CH₂CH₂SiCH₃(OCH₃)₂;

CF₃(C₆H₄)C₂H₄SiCH₃(OCH₃)₂;

CF₃(CF₂)₃(C₆H₄)C₂H₄SiCH₃(OCH₃)₂;

CF₃(CF₂)₅(C₆H₄)C₂H₄SiCH₃(OCH₃)₂;

CF₃(CF₂)₇(C₆H₄)C₂H₄SiCH₃(OCH₃)₂;

CF₃(CF₂)₃CH₂CH₂Si(OCH₂CH₃)₃;

CF₃(CF₂)₅CH₂CH₂Si(OCH₂CH₃)₃;

CF₃(CF₂)₇CH₂CH₂Si(OCH₂CH₃)₃;

CF₃(CF₂)₉CH₂CH₂Si(OCH₂CH₃)₃;

CF₃(CF₂)₇SO₂N(C₂H₅)C₂H₄CH₂Si(OCH₃)₃

By using polysiloxane containing aforementioned fluoroalkyl group isused as a binder, the ink-repellent properties in aphotocatalyst-containing layer are remarkably improved and the functionof preventing a coating material for a shading part or an ink for an inkjet system from adhering is manifested.

In addition, as a reactive silicone of the aforementioned (2), mentionmay be made of compounds having a chemical structure represented by thefollowing general formula:

wherein n is an integer of not smaller than 2, R¹ and R² are eachsubstituted or unsubstituted alkyl, alkenyl, aryl or cyanoalkyl grouphaving 1-10 carbon numbers, respectively, and not greater than 40% ofthe whole in moles is vinyl, phenyl or halogenated phenyl. In addition,the compounds wherein R¹ and R² are methyl group are preferable becausethe surface energy becomes the smallest. Am amount of not smaller than60% in terms of a mole rate of methyl group is preferable. In addition,a molecular chain has at least one reactive group such as hydroxy groupat an end of a chain and a side chain.

In addition, an stable organosilicon compound which does not perform across-linking reaction such as dimethylpolysiloxane may be mixed into abinder together with the aforementioned organopolysilicon.

In the color filter of the invention, various binders such asorganopolysiloxane and the like can be used in aphotocatalyst-containing layer like this. In the present invention, asdescribed above, fluorine in the surface of a photocatalyst-containinglayer may be reduced and, thereby, an inkphilic region may be formedwithin an ink-repellent region by incorporating fluorine in aphotocatalyst-containing layer containing such the binder and thephotocatalyst and pattern-irradiating with the energy. Upon this,fluorine needs to be contained in a photocatalyst-containing layer and,as a method of incorporating fluorine into such thephotocatalyst-containing layer containing a binder, mention may be madeof a method of binding a fluorine compound with a binder which usuallyhave the high binding energy, using the relatively weak binding energy,and a method of mixing into a photocatalyst-containing layer a fluorinecompound which is bound by the relatively weak binding energy. Byintroducing fluorine by such the method, when the energy is irradiated,a fluorine-bound site having the relatively small binding energy isfirst degraded and, thereby, fluorine can be removed from aphotocatalyst-containing layer.

As the aforementioned first method, that is, a method of binding afluorine compound with a binder which have the high binding energy usingthe relatively weak binding energy, mention may be made of a method ofintroducing a fluoroalkyl group as a substituent into the aforementionedorganopolysiloxane.

For example, as a method of obtaining organopolysiloxane,organopolysiloxane which exerts the great strength can be obtained byhydrolyzing and polymerization condensing chloro or alkoxysilane and thelike by a sol-gel reaction, which is described as (1). Here, in thismethod, organopolysiloxane is obtained by hydrolyzing and condensing orcohydrolyzing and condensing one or more of silicon compoundsrepresented by the general formula:

Y_(n)SiX_((4−n))

(wherein Y represents alkyl group, fluoroalkyl group, vinyl group, aminogroup, phenyl group or epoxy group, X represents alkoxyl group, acetylgroup or halogen, and n is an integer of 0 to 3) as described above. Byusing a silicon compound having a fluoroalkyl group as a substituent Yin this general formula, organopolysiloxane having a fluoroalkyl groupas a substituent can be obtained. When such the organopolysiloxanehaving a fluoroalkyl group as a substituent group is used as a binder,since a part of a carbon-carbon bond of a fluoroalkyl group is degradedby the action of a photocatalyst in a photocatalyst-containing layerupon the energy irradiation, the fluorine content of a part of thesurface of a photocatalyst-containing layer irradiated with the energycan be reduced.

As a silicon compound having a fluoroalkyl group using upon this, asilicon compound having at least one fluoroalkyl group and in which anumber of a carbon element in this fluoroalkyl group is 4 to 30,preferably 6 to 20, particularly preferably 6 to 16 is suitably used,being not limiting. Specific examples of such the silicon compound aredescribed as above and, inter alia, the silicon compound having afluoroalkyl group in which a number of carbon element is 6 to 8 ispreferable.

In the present invention, such the silicon compound having a fluoroalkylgroup may by used by mix with a silicon compound having no fluoroalkylgroup as described above, and a co-hydrolyzed and condensed compound ofwhich may be used as the organopolysiloxane. Alternatively, one or moreof such the silicon compounds having the fluoroalkyl group may be used,and a hydrolyzed and condensed compound or a co-hydrolyzed and condensedcompound of which may be used as the organopolysiloxane.

In organopolysiloxane having a fluoroalkyl group thus obtained, it ispreferable that, among silicon compounds constituting thisorganopolysiloxane, the silicon compound having a fluoroalkyl group iscontained at an amount of not less than 0.01 mol %, preferably not lessthan 0.1 mol %.

The reasons are as follows. By incorporating such the degree offluoroalkyl group, the ink-repellent properties on aphotocatalyst-containing layer can be enhanced and the difference in thewettability between a part of an ink-repellent region and a part whichwas converted into an inkphilic region by the energy irradiation can bemade to be larger.

In addition, in the method shown by the above (2), organopolysiloxane isobtained by cross-linking a reactive silicone having the excellentwater-repellency and oil-repellency. Similarly also in this case, byusing a substituent containing fluorine such as fluoroalkyl group andthe like as either R¹ or R² in the above general formula or both,fluorine can be contained in a photocatalyst-containing layer. Inaddition, since a part of a fluoroalkyl group having the smaller bindingenergy than siloxane bond is degraded when the energy is irradiated, thefluorine content in the surface of a photocatalyst-containing layer canbe reduced by the energy irradiation.

On the other hand, as an example of the latter, that is, a method ofintroducing a fluorine compound which is bound by the weaker energy thanthe binding energy of a binder, mention may be made of a method ofmixing a fluorine-contained surfactant therein when a fluorine compoundhaving a low molecular weight is introduced and, as a method ofintroducing a fluorine compound having a high molecular weight, mentionmay be made of a method of mixing a fluorine-contained resin having thehigh compatibility with a binder resin.

In the present invention, a photocatalyst-containing layer may contain asurfactant besides the aforementioned photocatalyst and binder. Moreparticularly, mention may be made of a hydrocarbon nonionic surfactantsuch as NIKKOL BL, BC, BO, BB series manufactured by Nikko ChemicalsCo., ltd., and a fluorine-contained or silicone-contained nonionicsurfactant such as ZONYL FSN, FSO manufactured by Dupont Co., Ltd.,Surfron S-141 and 145 manufactured by Asahi Glass Co., Ltd., MegafackF-141 and 144 manufactured by Dainippon Ink & Chemicals Co., Ltd.,Ftagent F-200 and F251 manufactured by Neos Co., Ltd., Unidyne DS-401and 402 manufactured by Daikin Industries, Ltd., Florad FC-170 and 176manufactured by 3M Co., Ltd. Alternatively, cationic surfactant, anionicsurfactant and amphoteric surfactant may be used.

In addition, a photocatalyst-containing layer may contain an oligomerand a polymer such as polyvinylalcohol, unsaturated polyester, acrylicresin, polyethylene, diallyl phthalate, ethylene propylene dienemonomer, epoxy resin, phenol resin, polyurethane, melamine resin,polycarbonate, polyvinyl chloride, polyamide, polyimide, styrenebutadiene rubber, chloroprene rubber, polypropylene, polybutylene,polystyrene, polyvinyl acetate, polyester, polybutadiene,polybenzimidazole, polyacrylnitrile, epichlorhydrin, polysulfide,polyisoprene, and the like in addition to the aforementionedsurfactants.

The content of a photocatalyst in a photocatalyst-containing layer canbe set in a range of 5 to 60% by weight, preferably 20 to 40% by weight.In addition, the thickness of a photocatalyst-containing layer ispreferably in a range of 0.05 to 10 μm.

The aforementioned photocatalyst-containing layer can be formed bydispersing a photocatalyst and a binder and, if needed, other additivesin a solvent to prepare a coating solution, and applying this coatingsolution. As a solvent used, an alcoholic organic solvent such asethanol, isopropanol and the like is preferable. Applying can beperformed by the known applying method such as spin coating, spraycoating, dip coating, roll coating, bead coating or the like. When anultraviolet-curing type binder is contained as a binder, aphotocatalyst-containing layer can be formed by performing the curingtreatment by the ultraviolet ray irradiation.

(Picture Element Part)

In the aforementioned first embodiment, a picture element part 6 isprovided on a wettability-variable layer 5, inter alia, theaforementioned photocatalyst-containing layer as shown in FIG. 1 andFIG. 2. In the first embodiment, a picture element part is formed in aninkphilic region having the low contact angle with a liquid in thepredetermined pattern by a plurality of colors of inks with an ink jetsystem by exposing the aforementioned photocatalyst-containing layer. Apicture element part is usually formed of three colors of red (R), green(G) and blue (B). The coloring pattern and an area to be colored in thispicture element part can be set arbitrarily.

Inks for an ink jet system for forming such the picture element part areroughly divided into an aqueous ink and an oil based ink. Although anyink can be used in the present invention, an aqueous ink based on wateris preferable in a respect of the surface tension.

Water alone or a mixed solvent of water and a water-soluble organicsolvent can be used as a solvent for an aqueous ink used in the presentinvention. On the other hand, an ink based on a solvent having a highboiling point is preferably used for an oil based ink in order toprevent the choking of a head. As a coloring agent used for such the inkfor an ink jet system, the known pigments and dyes are widely used. Inaddition, insoluble or soluble resins may be contained in a solvent inorder to improve the dispersibility and the fixing properties. Othercomponents such as surfactant containing nonionic surfactant, cationicsurfactant and amphoteric surfactant; preservative; antifungal agent; pHadjusting agent; anti-foaming agent; ultraviolet absorbing agent;viscosity adjusting agent; surface tension adjusting agent and the likemay be added thereto as the occasion demands.

In addition, although the conventional ink for an ink jet system can notcontain a large amount of a binder resin due to the low suitableviscosity, it is possible to impart the fixing ability to a coloringagent itself by granulating so as to wrap a coloring agent particle witha resin in an ink. Such the ink can be also used in the presentinvention. Further, so-called hot melt ink and UV-curing ink may beused.

In the present invention, inter alia, an UV-curing ink is preferablyused. By using a UV-curing ink, a picture element part is formed bycoloring with an ink jet system and, thereafter, UV is irradiated and,thereby, an ink can be cured rapidly which can sent to a next stepimmediately. Therefore, a color filter can be manufactured effectively.

Such the UV-curing ink has a prepolymer, a monomer, aphotopolymerization initiator and a coloring agent as a main component.As a prepolymer, any prepolymer such as polyesteracrylate,polyurethaneacrylate, eposyacrylate, polyetheracrylate, oligoacrylate,alkydacrylate, polyolacrylate, siliconacrylate and the like can be usedwithout limitation.

As a monomer, vinyl monomer such as styrene, vinyl acetate and the like;monofunctional acrylic monomer such as n-hexylacrylate andphenoxyethylacrylate; and multifunctional acrylic monomer such asdiethylene glycol diacrylate, 1,6-hexanediol diacrylate, hydroxypipericester neopentylglycol diacrylate, trimethylolpropane triacrylate,dipentaerhythritolhexane acrylate and the like can be used. Theaforementioned prepolymers and monomers may be used alone or in amixture of two or more of them.

As a photopolymerization initiator, an initiator which imparts thedesired curing properties and the desired recording properties can beselected for use among isobutylbenzoin ether, isopropylbenzoin ether,benzoin ethyl ether, benzoin methyl ether,1-phenyl-1,2-propadione-2-oxime, 2,2-dimethoxy-2-phenylacetophenone,benzil, hydroxycyclohexyl phenyl ketone, diethoxyacetophenone,2-hydroxy-2-methyl-1-phenylpropane-1-one, benzophenone,chlorothioxanthone, 2-chlorothioxanthone, isopropylthioxanthone,2-methylthioxanthone, chlorine-substituted benzophenone,halogen-substituted alkyl-allylketone and the like. Other componentssuch as photoinitiator assistant such as aliphatic amine, aromatic amineand the like; photosensitizer such as thioxanthosone and the like may beadded thereto as the occasional demands.

(Shading Part)

In the first embodiment of the present invention, a shading part 3 isformed on a transparent substrate 2 and in a border part of theaforementioned picture element part forming portion 4 as shown in FIG. 1and FIG. 2.

It is preferable that a shading part in the present invention is formedby forming a metal film of chromium or the like having the thickness ofaround 1000 to 2000 Å by a sputtering method, a vacuum metallizingmethod or the like and patterning this film. As this patterning method,the conventional patterning method such as sputtering and the like canbe used.

Alternatively, the shading part may be a layer containing a shadingparticle such as a carbon fine particle, a metal oxide, an inorganicpigment, an organic pigment, and the like in a resin binder. As a resinbinder used, alone or a mixture of two or more of a polyimide resin, anacrylic resin, an epoxy resin, polyacrylamide, polyvinyl alcohol,gelatin, casein, cellulose and the like, a photosensitive resin, an O/Wemulsion-type resin composition, for example, an emulsified reactivesilicone can be used. The thickness of such the resin shading part canbe set in a range of 0.5 to 10 μm. As a method of patterning such theresin shading part, methods which are generally used such as aphotolithography method and a printing method can be used.

(Transparent Substrate)

In the first embodiment of the present invention, the aforementionedshading part 3 or wettability-variable later 5, inter alia, theaforementioned photocatalyst-containing layer is provided on atransparent substrate 2 as shown in FIG. 1 and FIG. 2.

As this transparent substrate, substrates which have hitherto been usedfor a color filter can be used, without limitation, such as atransparent rigid material having no flexibility such as quartz glass,Pyrex glass, synthetic quartz glass and the like, or a transparentflexible material having the flexibility such as a transparent resinfilm, a resin plate for optics and the like. Among them, 7059 glassmanufactured by Corning Co., Ltd. is a material having the small thermalexpansion coefficient and is excellent in the dimensional stability andthe workability at heat-treatment at an elevated temperature and,additionally, since it is non-alkali glass containing no alkalinecomponent in a glass, it is suitable for a color filter for a colorliquid crystal display apparatus by an active matrix system. In thepresent invention, a transparent material is usually used for atransparent substrate and a reflective substrate and white-coloredsubstrate may be used. Alternatively, as a transparent substrate,substrates having the surface treated for preventing the alkalidissolution or for imparting the gas barrier properties or for otherobjects may be used.

(Ink-repellent Convex Part)

In the first embodiment of the present invention, an ink-repellentconvex part 7 may be formed on a wettability-variable layer 5 whichcovers an upper part of a shading part 3 as shown in FIG. 2. Thecomposition of such the ink-repellent convex part is not particularlylimited as long as it is a resin composition having the ink-repellentproperties. In addition, the composition is not necessarily transparentand may be colored. For example, a material which is used for a blackmatrix (shading part) and which is a material with no black materialincorporated therein can be used. More particularly, mention may be madeof a composition of a water soluble resin such as polyacrylamide,polyvinyl alcohol, gelatin, casein, cellulose and the like alone or amixture of two or more of them, and a resin composition such as OWemulsion, for example, an emulsified reactive silicone. In the presentinvention, a photocuring resin is suitable used for the reasons of easyhandling and curing. In addition, since this ink-repellent convex partis preferable as it grows ink-repellent, the surface thereof may betreated with an ink-repellent treating agent such as a silicone compoundand a fluorine-containing compound.

An ink-repellent convex part in the aforementioned first embodiment ispreferably relatively higher because it is provided for preventing anink from mixing upon coloring with an ink jet system but, in view of theflatness of the whole when it is made into a color filter, the thicknessnear that of a picture element part is preferable. More particularly, itis usually preferably in a range of 0.1 to 2 μm although it is differentdepending upon an accumulated amount of an ink blown.

(Protecting Layer)

In the first embodiment, a protecting layer may be further formed on apicture element part 6 though not shown in FIG. 1 or FIG. 2. Thisprotecting layer is provided for flattening a color filter and at thesame time preventing components contained in a picture element part, ora picture element part and a photocatalyst-containing layer fromdissolving into a liquid crystal layer.

The thickness of a protecting layer can be set in view of the lighttransmittance of a material used, the surface condition of a colorfilter and the like and, for example, it can be set in a range of 0.1 to2.0 μm. A protecting layer can be formed using a resin having the lighttransmittance required for a transparent protecting layer among theknown transparent photosensitive resin, two-pack curing type transparentresin and the like.

The Second Embodiment

The second embodiment of the present invention is a color filter inwhich a wettability-variable layer is formed on the whole a surface of atransparent substrate and a picture element part and a shading part areprovided at the predetermined position on this wettability-variablelayer. This indicates an example in which a wettability-variable layeris provided for forming a picture element part and a shading part andone specified example of the aforementioned color filter in which atleast a picture element part is provided on a wettability-variablelayer.

FIG. 3 shows an example of the second embodiment. This color filter 1 isformed of a wettability-variable layer 5 provided on a transparentsubstrate 2, a shading part 3 and a picture element part 6 formed onthis wettability-variable layer 5 and a protecting layer 8 provided onthis picture element part 6 and shading part 3.

In this color filter of the second embodiment, a picture element part 6and a shading part 3 are formed on a wettability-variable layer 5.However, as described in detail in a process for production, thewettability is reduced by irradiating a picture element part formingportion of a picture element part 6 with the energy in advance, and apicture element part 6 is formed on this part and, thereafter, thewettability of a wettability-variable layer 5 in a shading part formingportion of a shading part 3 is reduced and a shading part 3 may beformed thereon or, alternatively conversely, the wettability of ashading part forming portion is reduced in advance and a shading part isformed and, thereafter, the wettability of a wettability-variable layerof a picture element part forming portion is reduced and a pictureelement part 6 may be formed.

In either method for producing a color layer, since an inkphilic regionis formed in which the wettability of a wettability-variable layer isreduced when a picture element part 6 is formed, an ink is uniformlyspread within this picture element part forming portion when the ink isadhered with an ink jet system, and a color filter having no colornonuniformity can be obtained. In addition, upon coloring of a pictureelement part with an ink jet system, a shading part 3 is formed in itssurroundings, or the surroundings are the state where the wettability ofa wettability-variable layer is not changed, that is, an ink-repellentregion. Therefore, inks are not mixed over this part and a color filterhaving no disadvantages such as color mixing and the like can beobtained.

Since a material and the like of a transparent substrate 2, a shadingpart 3, a wettability-variable layer 5, a picture element part 6 and aprotecting layer 8 used in this embodiment are similar to those of theaforementioned first embodiment, they are not explained here. Inaddition, in this embodiment, since a shading part is formed on awettability-variable layer, a shading part is easily formed by forming apart having the better wettability in a wettability-variable layer inadvance and applying a coating material for a shading part on the part.Therefore, it can be said that a shading part is preferably formed usinga coating material for a shading part obtained by dissolving theaforementioned shading fine particle and a resin in a solvent or thelike.

The Third Embodiment

The third embodiment of the present invention is a color filter in whichthe aforementioned shading part is provided on a transparent substrate,a wettability-variable layer is provided on a picture element partforming portion on the transparent substrate, which is a part on which apicture element part is to be formed, and a picture element part isprovided on this wettability-variable layer. This shows an example inwhich a wettability-variable layer is provided for forming a pictureelement part and a shading part and, as described above, is onespecified examples of a color filter in which at least a picture elementpart is provided on a wettability-variable layer.

FIG. 4 shows one example of the third embodiment. This color filter 1 isformed of a shading part 3 provided on a transparent substrate 2, awettability-variable layer 5 formed in a pattern like state on a pictureelement part forming portion 4 which is a region between theaforementioned shading parts 3 on a transparent substrate 2, a pictureelement part 6 formed on this wettability-variable layer 5 and further aprotecting layer 8 formed on this picture element part 6 and shadingpart 3.

The characteristics of this embodiment are in that awettability-variable layer is provided on only a picture element partforming portion 4 on a transparent substrate 2 and awettability-variable layer 5 is not formed on a shading part formingportion on which a shading part 3 is to be formed. Since awettability-variable layer 5 is formed on only a picture element partforming portion in the third embodiment like this, when the wettabilityis changed by adding the stimulation to a wettability-variable layer,the stimulation may be added over the whole side and the stimulationdoes not necessarily be added in a pattern like state. Therefore, thereare effects that steps after formation of a wettability-variable layermay be simplified.

In this embodiment, since a shading part 3 is provided just on atransparent substrate 2, it is preferable that a transparent substrate 2is inkphilic. In particular, when a wettability-variable layer 5 isformed in a pattern like state and, thereafter, a shading part 3 isformed on a shading part forming portion therebetween, it is preferablethat a surface of a transparent substrate 2 is an inkphilic regioncompared with a wettability-variable layer which is an ink-repellentregion before the change in the wettability in view of formation of ashading part 3. Therefore, in the third embodiment, it is preferablethat the wettability on a transparent substrate 2 is less than 10degrees as the contact angle with a liquid having the surface tension of40 mN/m, more preferably less than 5 degrees, particularly preferablyless than 1 degree.

As a transparent substrate, the surface of which is an inkphilic region,there are a substrate formed of an inkphilic material, a substrateobtained by treating the surface of a material so as to make the surfaceinkphilic, and an inkphilic layer is formed on a transparent surface,being not limiting in this embodiment.

As an example in which the surface of a material is treated so as tomake the surface inkphilic, mention may be made of the inkphilic surfacetreatment with the plasma treatment utilizing argon and water, and as aninkphilic layer provided on a transparent substrate, mention may be madeof a silica membrane obtained by a sol-gel method usingtetraethoxysilane.

Since materials and the like used in this embodiment other than atransparent substrate 2, that is, a shading part 3, awettability-variable layer 5, a picture element part 6 and a protectinglayer 8 are similar to those of the aforementioned first embodiment,they are not explained here.

The Fourth Embodiment

The fourth embodiment of the present invention is a color filter inwhich a shading part is formed on a transparent substrate, awettability-variable layer is formed on this shading part, and a pictureelement part is formed between the wettability-variable layers. Thisshows an example in which a wettability-variable layer is provided forforming a picture element part and one of specified examples of theaforementioned color filter in which a wettability-variable layer isprovided on a border part of a picture element part.

FIG. 5 shows one example of the present fourth embodiment. In this colorfilter 1, a shading part 3 is formed on a transparent substrate 2, and awettability-variable layer 5 is formed on this shading part 3. Further,a picture element part 6 is formed on a part between thewettability-variable layers 5. And, a protecting layer 8 is formed sothat it covers an upper part of this picture element part 6 andwettability-variable layer 5. In this embodiment, since awettability-variable layer is formed in a pattern like state, thewettability of a wettability-variable layer may be changed by adding thestimulation over the whole surface, for example, the pattern-irradiationof the energy utilizing a mask does not necessarily need to be performedupon formation of a picture element part 6 and steps can be simplified.In addition, since a wettability-variable layer 5 is formed on only aborder part of a picture element part 6, an amount thereof to be used isextremely small. Therefore, it is effective, for example, when there isa problem on applying of a large amount of a wettability-variable layeron a color filter that it is expensive.

Here, the width of this wettability-variable layer 5 is preferablyformed narrower than that of a shading part 3. Since the width of thiswettability-variable layer 5 is narrower than that of shading part 3,the width of a picture element part 6 formed betweenwettability-variable layers can be formed larger than that of an openingof a shading part 3. Thereby, disadvantages such as color missing can beprevented.

In addition, in this embodiment, since a shading part 3 and a pictureelement part 6 are formed just on a transparent substrate 2, it ispreferable that a transparent substrate 2 is inkphilic on the surfacethereof. In particular, when a picture element part 6 is formed betweenwettability-variable layers 5 by adhering with an ink jet system, an inkis uniformly spread as the wettability on this transparent substrate 2grows more inkphilic and disadvantages such as color nonuniformity andthe like hardly occur. Therefore, also in the fourth embodiment, as inthe third embodiment, it is preferable that the wettability on atransparent substrate 2 is less than 10 degrees as the contact anglewith a liquid having the surface tension of 40 mN/m.

Regarding materials used in this embodiment, a material for atransparent substrate is similar to that of the third embodiment andother materials are similar to those of the first embodiment, they arenot explained here.

The Fifth Embodiment

The fifth embodiment of the present invention is a color filter in whicha wettability-variable layer is formed on a shading part forming portionon a transparent substrate on which a shading part is to be formed, ashading part is formed on this wettability-variable layer and a pictureelement part is formed between the shading parts. This shows an examplein which a wettability-variable layer is provided for forming a pictureelement part and a shading part and one of specific examples of theaforementioned color filter in which a wettability-variable layer isprovided on a border part of a picture element part.

FIG. 6 shows one example of the present fifth embodiment of the presentinvention. In this color filter 1, wettability-variable layer 5 isformed in a pattern like state on a shading part forming portion 9 on atransparent substrate 2 on which a shading part is to be formed, and apicture element part 6 is formed on a transparent substrate 2 betweenthe wettability-variable layers 5 formed in a pattern like state. Inaddition, a shading part 3 is formed on the aforementionedwettability-variable layer 5.

In this embodiment, since a wettability-variable layer is formed in thepattern-like and the stimulation may be added to the whole surface inorder to change the wettability of a wettability-variable layer, forexample, it is not necessary to perform the pattern-irradiation of theenergy utilizing a mask upon formation of a picture element part 6 andsteps can be simplified. In addition, as in the fourth embodiment, sincea wettability-variable layer 5 is formed on only a border part of apicture element part 6 and, in the case of this embodiment, on only ashading part forming portion 9, an amount thereof to be used is small.Therefore, it is effective when there is a problem on formation of alarge amount of a wettability-variable layer on a color filter.

In addition, in this embodiment, since a picture element part 6 isformed just on a transparent substrate 2 as in the aforementioned forthembodiment, it is preferable that a transparent substrate 2 is inkphilicon the surface. Therefore, also in the fifth embodiment, as in the thirdembodiment and the fourth embodiment, it is preferable that thewettability on a transparent substrate 2 is less than 10 degrees as thecontact angle with a liquid having the surface tension of 40 mN/m.

As materials used in this embodiment, a material for a transparentsubstrate is similar to that of the aforementioned third embodiment andother materials are similar to those of the aforementioned firstembodiment, they are not explained here.

B. A Process for Producing a Color Filter

Then, a process for producing a color filter of the present inventionwill be explained using some embodiments.

The Sixth Embodiment

The sixth embodiment of the present invention is a process for producinga color filter which is the aforementioned first embodiment in thepresent invention, and said process has

(1) a step of forming a shading part on a transparent substrate;

(2) a step of providing, on a surface of the transparent substrate onwhich a shading part was formed, a photocatalyst-containing layer havingthe wettability of a part irradiated with the energy which changed in adirection of reduction of a contact angle with a liquid;

(3) a step of irradiating with the energy a picture element part formingportion on this photocatalyst-containing layer on which a pictureelement part is to be formed, to form an exposed part for a pictureelement part; and

(4) a step of coloring this exposed part for a picture element part withan inkjet system to form a picture element part.

(Explanation of Each Step)

FIG. 7 is for explaining each step of the sixth embodiment of thepresent invention. In this example, first, a shading part 3 is formed ona transparent substrate 2 by the conventional method (FIG. 7(A)). Aprocess for manufacturing this shading part 3 is not particularlylimited, for example, mention may be made of a method of forming it byforming a metal film such as chrome having the thickness of around 1000to 2000 Å by a sputtering method, a vacuum-metallizing method or thelike and patterning this film.

Then, a photocatalyst-containing layer 5 is formed on a transparentsubstrate 2 on which this shading part 3 is formed (FIG. 7(B)). Thisphotocatalyst-containing layer 5 is formed by dispersing theaforementioned photocatalyst and binder in a solvent, if necessary,together with other additives to prepare a coating solution, applyingthis coating solution, and proceeding the hydrolyzing and polymerizationcondensing reaction to fix firm a photocatalyst in a binder. As asolvent, alcoholic organic solvents such as ethanol, isopropylalcoholand the like are preferable, and applying can be performed by the knownapplying method such as spin coating, spray coating, dip coating, rollcoating, bead coating or the like.

A transparent substrate 2 on which a photocatalyst-containing layer 5 isformed is pattern-irradiated with the energy 10 such as the ultravioletlight or the like using a mask 11. Thereby, there is formed an exposedpart for a picture element part 12 in which a picture element partforming portion on a photocatalyst-containing layer 5 on which a pictureelement part is to be formed, was converted into an inkphilic region bythe action of a photocatalyst in a photocatalyst-containing layer 5(FIG. 7(C)).

When exposure is performed using a photomask 11 for forming an exposedpart for a picture element part 12 like this, it is preferable that thewidth of an exposed part for a picture element part 12 formed by theenergy irradiation, that is, the width of a picture element part to beformed, is wider than that of an opening formed by a shading part 3.This is because such the width eliminates a possibility that thebacklight passes through a part on which a picture element part is notformed when irradiated with the backlight after the completion of aliquid crystal panel, and disadvantages such as color missing and thelike do not occur.

This energy irradiation can be also performed by the whole surfaceexposure from a transparent substrate 2 side as shown in FIG. 8. Whenthe whole surface is irradiated with the energy from a transparentsubstrate 2 side, a shading part exerts as a mask as apparent from FIG.8 and the exposure is performed on only a part having no shading part 3.According to this method, since the energy irradiation can be performedwithout using a mask for forming a picture element part, it can be saidto be advantageous in a respect of cost.

In addition, when the energy is irradiated from a transparent substrate2 side, it is preferable that a material through which the energy passesis used for a transparent substrate 2 and, for example, when the lightincluding the ultraviolet light is used as the energy, a materialthrough which the ultraviolet light passes such as quarts is preferablyused.

Using an ink jet apparatus 13, an ink 14 is injected into an exposedpart for a picture element part 12 thus formed, which was converted intoan inkphilic region by the energy irradiation to color the part withred, green and blue (FIG. 7(D)). In this case, since the interior of anexposed part for a picture element part 12 was made into an inkphilicregion having the small contact angle with a liquid by the energyirradiation as described above, an ink 14 injected from an ink jetapparatus 13 is spread uniformly in an exposed part for a pictureelement part 12. In addition, since a region of aphotocatalyst-containing layer not exposed was a part of anink-repellent region, an ink is repelled in this region and removedtherefrom.

An ink jet apparatus used in the present invention is not particularlylimited but an ink jet apparatus can be used which uses various methodssuch as a method of injecting a charged ink continuously and controllingwith the magnetic field, a method of injecting an ink intermittentlyusing a piezo-element, a method of injecting an ink intermittently byheating the ink and utilizing its bubbling.

A picture element part 6 is formed by solidifying the ink thus adheredto an exposed part for a picture element part 12 (FIG. 7(E)). In thepresent invention, the solidification of an ink is carried out byvarious methods depending upon a kind of an ink used. For example, inthe case of a water-soluble ink, the solidification is performed byremoving water by heating or the like.

In view of this step of solidifying an ink, as a kind of an ink used inthe present invention, an ink is preferably a UV-curing ink. This isbecause since a UV-curing ink can be rapidly solidified by the UVirradiation, a time for producing a color filer can be shortened.

As described above, since an ink in an exposed part for a pictureelement part 12 is uniformly spread, when an ink is solidified likethis, a picture element part 6 having neither color missing nor colornonuniformity can be formed. And, a protecting layer may be furtherprovided thereon as necessary.

By performing such the each step, a color filter of the first embodimentof the present invention shown in FIG. 1 can be manufactured.

(Ink-repellent Convex Part)

The sixth embodiment of the present invention may has a step ofirradiating a photocatalyst-containing layer on a shading part with theenergy pattern irradiation to form an exposed part for an ink-repellentconvex part and forming an ink-repellent convex part in this exposedpart for an ink-repellent convex part after a step of provision of aphotocatalyst-containing layer.

A step of forming this ink-repellent convex part will be explained usingFIG. 9. According to the same manner as in the aforementioned sixthembodiment shown in FIG. 7, a shading part 3 is formed on a transparentsubstrate 2 and a photocatalyst-containing layer 5 is formed so as tocover the above, and thus obtained member is irradiated with the energyvia a mask for an ink-repellent convex part 15 (FIG. 9(A)). Bypattern-irradiating the energy via a mask for an ink-repellent convexpart, an exposed part for an ink-repellent convex part 16 is formed on aphotocatalyst-containing layer 5 on a shading part.

An ink for an ink-repellent convex part 17 such as a UV-curing resinmonomer is adhered to this exposed part for an ink-repellent convex part16 by an ink jet apparatus 13 (FIG. 9(B)). A method of applying this inkfor an ink-repellent convex part is not limited to a method by an inkjet apparatus but other methods, for example, dip coating and the likemay be used.

And, by curing an ink for an ink-repellent convex part 17 by UVirradiation or the like, an ink-repellent convex part 7 is formed on thesurface of a photocatalyst-containing layer 5 on a shading part 3 (FIG.9(C)). The width of this ink-repellent convex part 7 is preferablyformed narrower than that of a shading part 3 as shown in a figure. Thisis because such the formation does not lead to a problem such as colormissing and the like as described above.

By irradiating the whole surface or pattern-irradiating with the energy10 from a side of a photocatalyst-containing layer 5, to the thus formedmember in which an ink-repellent convex part 7 is formed on aphotocatalyst-containing layer 5, a part other than a part on which anink-repellent convex part 7 is formed, is exposed and made into anexposed part for a picture element part and, thereafter, according tothe aforementioned manner, an ink 14 is injected and adhered to thispart using an ink jet apparatus 13 and cured to form a picture elementpart 6 and, thus, a color filter with an ink-repellent convex part 7provided thereon can be manufactured (FIGS. 9(D), (E), (F)).

In this method, since an exposed part for an ink-repellent convex partis provided by pattern-irradiating a photocatalyst-containing layer on ashading part with the energy, an ink-repellent convex part having anarbitrary width can be formed. Therefore, by applying an ink for anink-repellent convex part thereon, an ink-repellent convex part havingan arbitrary width can be formed. Hence, by adjusting the width of amask for an ink-repellent convex part 15, an ink-repellent convex part 7having the narrower width than that of the aforementioned shading part 3can be formed. By forming such the ink-repellent convex part 7 havingthe narrower width than that of a shading part 3, since the width of apicture element part 6 formed between the ink-repellent convex parts 7can be wider than that of an opening of a shading part 3, a color filterhaving no disadvantages such as color missing and the like can beobtained as described above.

In addition, in this embodiment, an ink-repellent convex part is formedby utilizing the change in the wettability of a photocatalyst-containinglayer but the formation is not limited to this in the present inventionand, for example, an ink-repellent convex part may be provided by aphotolithography or the like.

(A Method of Forming a Picture Element Part)

In the present invention, a picture element part 6 may be formed by onetime energy irradiation and adhesion of an ink to an exposed part as inthe aforementioned sixth embodiment but, in the sixth embodiment, adistance between exposed parts for a picture element part which are aninkphilic region irradiated with the energy upon adhesion of an ink, isshort. Therefore, there is a possibility that a problem such as the inkmixing and the like may occur upon formation of a picture element part.As a method of avoiding such the problem, mention may be made of amethod of dividing the energy irradiation and formation of a pictureelement part into at least two times.

FIG. 10 shows an example in which the energy irradiation and formationof a picture element part were performed by dividing into two times. Ashading part 3 is formed on a transparent substrate 2 as in theaforementioned example shown in FIG. 7, a member in which aphotocatalyst-containing layer 5 is formed on a transparent substrate 2so as to cover this shading part 3, is irradiated with the energy 10using a mask 11′ so that a picture element part is formed on every otherpicture element part forming portion, to obtain an exposed part for apicture element part 12 (FIG. 10(A)). By adhering an ink 14 to thisexposed part for a picture element part 12 using an ink jet apparatus 13(FIG. 10(B)), a picture element part 6 is formed on every other apicture element part forming portion (FIG. 10(C)). It is preferable thata picture element part thus formed itself is ink-repellent in order toprevent second time coloration of an ink to this picture element part byan ink jet apparatus and the surface thereof may be treated with anink-repellent treating agent such as a silicone compound and afluorine-containing compound.

And, by irradiating again with the energy 10 from aphotocatalyst-containing layer 5 side on which a picture element part 6is formed alternately, a picture element part forming portion betweenpicture element parts 6 is exposed to form an exposed part for a pictureelement part 12 and, by adhering an ink 14 thereon using an ink jetapparatus 15, a color filter can be obtained (FIG. 10(D)).

According to this method, since it is also possible to shorten oreliminate a distance between each picture element part, a colored layer(aggregate of picture element parts) having the excellent flatness canbe formed. In addition, a distance between picture element parts uponfirst time formation of a picture element part is large, inks are notmixed over this part. Therefore, the high quality color filter having noink mixture and the like can be obtained.

In addition, in the aforementioned method, a picture element part 6 wasformed every other one first time, the present invention is not limitedthereto but the change may be performed by the shape of a pictureelement part of a color filter such as zigzag-like or the like so longas the first formed picture element parts are not in the vicinity. Inaddition, in the aforementioned explanation, a picture element part wasformed by dividing into two times but a picture element part may beformed by dividing into three times or more.

(Energy to be Irradiated)

In the present invention, the light including the ultraviolet light maybe used as the energy to be irradiated to a photocatalyst-containinglayer. As a light source including the ultraviolet light, for example,mention may be made of a mercury lamp, a metal halide lamp, a xenon lampand the like. The wavelength of the light used for this exposure can beset from a range of not greater than 400 nm, preferably not greater than380 nm. In addition, an amount of the light to be irradiated uponexposure may be an amount of irradiation necessary for an exposed partto express the inkphilic properties by the action of a photocatalyst.

When pattern-irradiation is necessary upon the energy irradiation,pattern-irradiation can be performed via a photomask using theaforementioned light source. Alternatively, as an another method, therecan also be used a method of picture-irradiating in a pattern like stateusing a laser such as excimer, YAG and the like. However, such themethod may lead to a problem that an apparatus is expensive, thehandling is difficult and further the continuous output can not beperformed.

Therefore, in the present invention, the pattern of an inkphilic regionmay be formed by adding the photocatalystic reaction initiating energyto a photocatalyst-containing layer, and adding the reaction rateincreasing energy to a region which received the photocatalysticreaction initiating energy in a pattern like state. The reasons are asfollows. By forming the pattern using such the energy irradiatingmethod, the reaction rate increasing energy such as the infrared laserwhich is relatively low cost and easily handled, can be used and theaforementioned problem does not occur.

The pattern of an inkphilic region having the changed wettability can beformed by the addition of such the energy based on the followingreasons. That is, first, by adding the photocatalystic reactioninitiating energy to a region on which the pattern is to be formed, thephotocatalystic reaction is initiated on a photocatalyst-containinglayer. Then, the reaction rate increasing energy is added in a regionwhich receives the photocatalystic reaction initiating energy. By addingthe reaction rate increasing energy like this, a reaction in aphotocatalyst-containing layer to which the photocatalystic reactioninitiating energy has been already added and in which a reaction hasbeen initiated by the catalytic action of a photocatalyst is rapidlyaccelerated. Then, by adding the reaction rate increasing energy for thepredetermined period, the change of the wettability in thephotocatalyst-containing layer is changed into the desired range and,thus, the pattern to which the reaction rate increasing energy has beenadded can be made into the pattern of an inkphilic region having thechanged wettability.

A. Photocatalystic Reaction Initiating Energy

The photocatalystic reaction initiating energy used for this energyirradiating method refers to the energy that a photocatalyst initiates acatalytic reaction for changing the properties of a compound in aphotocatalyst-containing layer.

An amount of the photocatalystic reaction irradiating energy to be addedis such the degree of an amount that does not cause the rapid change inthe wettability in a photocatalyst-containing layer. When an amount ofthe photocatalystic reaction initiating energy to be added is small,since the sensitivity upon formation of the pattern by adding thereaction rate increasing energy is lowered, being not preferable. On theother hand, when this amount is too large, the degree of the change inthe properties in a photocatalyst-containing layer to which thephotocatalystic reaction initiating energy has been added becomes toolarge and the difference between regions to which the reaction rateincreasing energy has been added and not added becomes unclear, beingnot preferable. An amount of the energy to be added is determined byperforming a preliminary experiment on an amount of the energy to beadded and the change in the wettability in a photocatalyst-containinglayer.

The photocatalystic reaction initiating energy in this method is notparticularly limited as long as the energy which can initiate thephotocatalystic reaction and, inter alia, the light is preferable.

A photocatalyst used in the present invention has the differentwavelength of the light, which initiates a catalytic reaction dependingupon the band gap thereof. For example, in the case of cadmiun sulfide,the wavelength is 496 nm and, in the case of iron oxide, the wavelengthis 593 nm of the visible light and, in the case of titanium oxide, thewavelength is 388 nm of the ultraviolet light. Therefore, the light canbe used in the present invention whether the visible light or theultraviolet light as long as the light. However, in the context thattitanium dioxide is suitably used as a photocatalyst because it iseffective as a photocatalyst due to the high band gap energy asdescribed above, chemically stable, has no toxicity and easilyavailable, the light is preferably the light containing the ultravioletlight which initiates a catalytic reaction of this titanium oxide. Moreparticularly, it is preferable that the ultraviolet light in a range ofnot greater than 400 nm, preferably not greater than 380 nm iscontained.

As the light source for such the light containing the ultraviolet light,mention may be made of various ultraviolet sources such as a mercurylamp, a metal halide lamp, a xenon lamp, an excimer lamp and the like.

In the present invention, a range to which this photocatalystic reactioninitiating energy is to be added may be a part of aphotocatalyst-containing layer. For example, by adding thisphotocatalystic reaction initiating energy in a pattern like state andfurther adding the reaction rate increasing energy also in a patternlike state, it is possible to form the pattern of an inkphilic regionhaving the changed wettability. However, for the reasons ofsimilification of steps and the like, it is preferable that thisphotocatalystic reaction initiating energy is added to the whole surfaceof a region on which the pattern is to be formed. It is preferable that,by adding the reaction rate increasing energy to a region to the wholesurface of which the photocatalystic reaction initiating energy has beenadded in a pattern like state, the pattern of an inkphilic region isformed on a photocatalystic-containing layer.

B. Reaction Rate Increasing Energy

Then, the reaction rate increasing energy used in this method will beexplained. The reaction rate increasing energy used in this methodrefers to the energy for increasing a reaction rate of a reactionchanging the wettability of a photocatalyst-containing layer which wasinitiated by the aforementioned photocatalystic reaction initiatingenergy. In the present invention, any energy can be used as long as itis the energy having such the action and, inter alia, the heat energy ispreferably used.

A method of adding such the heat energy to a photocatalyst-containinglayer in a pattern like state is not particularly limited as long as itcan form the pattern by the heat on a photocatalyst-containing layer butmention may be made of a method by the infrared laser, a method by aheat-sensitive head and the like. As such the infrared laser, mentionmay be made of the infrared YAG laser (1064 nm) having the advantagessuch as the strong directivity and the long irradiation distance, adiode laser (LED; 830 nm, 1064 nm, 1100 nm) having the advantages suchas the relatively low cost, a semiconductor laser, a He—Ne laser, acarbonic dioxide gas laser and the like.

In this method, the pattern of an inkphilic region can be formed basedon the difference in the reaction rate between a region to which thereaction rate increasing energy has been added and a region to which thereaction rate increasing energy has not been added, by adding theaforementioned photocatalystic reaction initiating energy and activatinga photocatalyst to initiate the change in the wettability by thecatalytic reaction in a photocatalyst-containing layer, and adding thereaction rate increasing energy to a part having the changed wettabilityto promote the catalytic reaction of the part.

The Seventh Embodiment

The seventh embodiment of the present invention is one of processes forproducing a color filter of the aforementioned second embodiment of thepresent invention, and comprises:

(1) a step of providing on a transparent substrate aphotocatalyst-containing layer having the wettability of theenergy-irradiated part which changes in a direction of reduction of thecontact angle with a liquid,

(2) a step of forming an exposed part for a shading part on a shadingpart forming portion on which a shading part is to be formed bypattern-irradiating with the energy on the transparent substrate,

(3) a step of forming a shading part on this exposed part for a shadingpart,

(4) a step of forming an exposed part for a picture element part byirradiating a transparent substrate on which this shading part wasprovided with the energy, and

(5) a step of coloring this exposed part for a picture element part withan ink jet system to form a picture element part.

FIG. 11 is for explaining each step of the seventh embodiment of thepresent invention. As shown in FIG. 11(A), a photocatalyst-containinglayer 5 is first formed on a transparent substrate 2. The formation ofthis photocatalyst-containing layer 5 can be performed according to thesame manner as that of the aforementioned sixth embodiment.

Then, a shading part forming portion of a photocatalyst-containing layer5 is pattern-irradiated with the energy 10 using a photomask for ashading part 19 to form an exposed part for a shading part 20. Thisexposed part for a shading part 20 is a part in which the contact anglewith a liquid is lowered by the action of a photocatalyst in aphotocatalyst-containing layer 5 and forms an inkphilic region (FIG.11(B)).

This energy 10 is the same as that of the aforementioned sixthembodiment and means not only the ultraviolet light but also otherenergy.

Then, after a coating material for a shading part 21 is adhered to anexposed part for a shading part 20 by an ink jet apparatus 13, thecoating material is cured to form a shading part 3 (FIG. 11(C)).Applying of a coating material for a shading part 21 on an exposed partfor shading part 20 may be also performed by the known applying methodsuch as spray coating, dip coating, roll coating, bead coating and thelike as well as the method using the aforementioned inkjet apparatus. Inthis case, the applied coating material for a shading part 10 isrepelled by an ink-repellent region of a photocatalyst-containing layer5 having the high contact angle with a liquid, other than an exposedpart for a shading part 20, to be removed therefrom, and is selectivelyadhered to only an exposed part for a shading part 20 which is aninkphilic region having the low contact angle with a liquid.

Further, the formation of a shading part 3 may be performed by a vacuumfilm forming method. That is, a metal film is formed on the exposedphotocatalyst-containing layer 5 by a vacuum metallizing method, whichcan be patterned by the peeling using an adhesive tape, the solventtreatment or the like utilizing the difference of the adhesive forcebetween a photocatalyst-containing layer 5 other than an exposed partfor a shading part 20 and an exposed part for a shading part 20, to forma shading part.

Then, a photocatalyst-containing layer 5 on which a shading part 3 wasformed is irradiated with the energy 10 on its whole surface or in apattern like state. By this, a part on which a shading part 3 is notformed, is made into an exposed part for a picture element part of aninkphilic region by the action of a photocatalyst in aphotocatalyst-containing layer 5 (FIG. 1(D)).

Then, an ink 14 is injected to an exposed part for a picture elementpart which was made into an inkphilic region by exposure using an inkjet apparatus 13, to color the part with red, green and blue (FIG.11(E)). In this case, since the interior of an exposed part for apicture element part has become an inkphilic region having the smallcontact angle with a liquid by the energy irradiation as describedabove, an ink 14 injected from an ink jet apparatus 13 is uniformlyspread in an exposed part for a picture element part.

By solidifying an ink thus adhered to an exposed part for a pictureelement part 11, a picture element part 6 is formed between shadingparts 3 (FIG. 11(F)). If necessary, a protecting layer may be furtherformed.

When a color filter is manufactured by such the process, since an ink inan exposed part for a picture element part 11 is uniformly spread, whenan ink 14 is solidified, a picture element part 5 having no colormissing, color nonuniformity and the like can be formed and, thus, thehigh quality color filter can be obtained.

The Eighth Embodiment

The eighth embodiment of the present invention is another process forproducing a color filter of the aforementioned second embodiment of thepresent invention, and comprises:

(1) a step of providing on a transparent substrate aphotocatalyst-containing layer having the wettability of theenergy-irradiated part which changes in a direction of reduction of thecontact angle with a liquid;

(2) a step of pattern-irradiating with the energy a picture element partforming portion on the transparent substrate, on which a picture elementpart is to be formed, to form an exposed part for a picture elementpart;

(3) a step of coloring this exposed part for a picture element part withan inkjet system to form a picture element part;

(4) a step of irradiating a photocatalyst-containing layer of a borderpart of at least the picture element part with the energy; and

(5) a step of forming a shading part on a border part of the pictureelement part irradiated with the energy.

FIG. 12 is for explaining this eighth embodiment and, as in the seventhembodiment, a substrate 2 in which a photocatalyst-containing layer 5 isfirst formed on its single side is formed (FIG. 12(A)). The energy 10 ispattern-irradiated via a mask 11 from a side of this transparentsubstrate 2 on which a photocatalyst-containing layer 5 is formed (FIG.12(B)). An ink 14 is adhered to an exposed part for a picture elementpart which has become an inkphilic region by the energy irradiationusing an ink jet apparatus 13 to form a picture element part 6 (FIG.12(C)).

Upon formation of this picture element part 6, a method of forming apicture element part by dividing the energy irradiation and theformation of a picture element part into two or more times as explainedin the aforementioned sixth embodiment may be used. This is because,upon the formation of a picture element part 6, since an ink-repellentregion is narrow between picture element parts 6, there is a possibilitythat inks may be mixed.

The surface on which a picture element part 6 is thus formed isirradiated with the energy 10 on the whole surface or in a pattern likestate, to change an ink-repellent region between picture element parts 6into an inkphilic region (FIG. 12(D)). Then, a shading part 3 can beformed by adhering a coating solution for a shading part 21 to a borderpart of this picture element part 6, for example, with an ink jetapparatus 13 and curing the coating material (FIGS. 12(E),(F)). Then, acolor filter can be obtained by forming a protecting layer on thesurface as necessary.

Since the energy, ink jet apparatus and various inks and the like whichare used in the eighth embodiment are similar to those of theaforementioned sixth embodiment, they are not explained here.

The Ninth Embodiment

The ninth embodiment of the present invention is a process for producinga color filter which is the third embodiment of the present invention,and comprises:

(1) step of forming a photocatalyst-containing layer having thewettability of the energy-irradiated part on a transparent substrate,which changes in a direction of reduction of the contact angle withliquid, on a picture element part forming portion which is a part on thetransparent substrate on which a picture element part is to be formed;

(2) a step of providing a shading part on a border part of the pictureelement part forming portion provided on the photocatalyst-containinglayer;

(3) a step of irradiating the photocatalyst-containing layer with theenergy to form an exposed part for a picture element part; and

(4) a step of coloring this exposed part for a picture element part withan ink jet system to form a picture element part.

This process is explained using FIG. 4. A photocatalyst-containing layer5 is first formed on a part on a transparent substrate 2, on which apicture element part is to be formed. That is, according to this method,a photocatalyst-containing layer 5 is first formed on a transparentsubstrate in a pattern like state. As a method of forming aphotocatalyst-containing layer in a pattern like state, for example,mention may be made of a method forming the layer by a photolithographyusing a photosensitive sol-gel solution, a method by printing and thelike.

A shading part 3 is formed on a part (shading part forming portion) onwhich a photocatalyst-containing layer 5 is not formed, on a transparentsubstrate 2 on which the thus formed photocatalyst-containing layer 5 isformed, with a coating material for a shading part or the like, forexample, using an ink jet system. Upon this, the wettability of thesurface of a transparent substrate 2 has been made into more inkphilicas compared with the wettability of a surface on aphotocatalyst-containing layer 5. Therefore, upon formation of a shadingpart 3, a coating material for a shading part is not adhered to aphotocatalyst-containing layer showing the ink-repellent properties andis adhered to only a shading part forming portion on a transparentsubstrate 2, to form a shading part.

In this embodiment, it is preferable that the wettability on atransparent substrate 2 is inkphilic. More particularly, it ispreferable that the wettability is less than 10 degrees as the contactangle with a liquid having the surface tension of 40 mN/m, morepreferably less than 5 degrees as the contact angle with a liquid havingthe surface tension of 40 mN/m, particularly preferably less than 1degree.

After a shading part 3 is formed like this, a photocatalyst-containinglayer 5 is irradiated with the energy to make the part into an inkphilicregion. A color filter can be formed by forming a picture element part 6on a photocatalyst-containing layer which was made into an inkphilicregion using an ink jet apparatus or the like and, as necessary, furtherforming a protecting layer.

Also in this embodiment, since the energy to be irradiated, ink jetapparatus and various inks are similar to those of the embodiments aspreviously explained, the explanation thereof is omitted.

The Tenth Embodiment

The tenth embodiment of the present invention is a process for producinga color filter which is the aforementioned fourth embodiment of thepresent invention, and comprises:

(1) a step of forming a shading part on a transparent substrate;

(2) a step of providing, on this shading part, aphotocatalyst-containing layer having the wettability of theenergy-irradiated part which changes in a direction of reduction of thecontact angle with a liquid; and

(3) a step of coloring a picture element part forming portion, on atransparent substrate on which the photocatalyst-containing layer is notformed, on which a picture element part is to be formed, with an ink jetsystem to form a picture element part.

This process is explained using FIG. 13. A shading part 3 is firstformed on a transparent substrate 2 (FIG. 13(A)). Then, aphotocatalyst-containing layer 5 is formed in a pattern like state onthis shading part 3 (FIG. 13(B)). Here, since a method of forming ashading part 3 and that for forming a photocatalyst-containing layer 5are similar to those of the aforementioned embodiments, the explanationthereof is omitted.

Here, it is preferable that the width of this photocatalyst-containinglayer 5 is formed narrower than that of a shading part 3 in thisembodiment. The reasons are as follows. By forming the width of aphotocatalyst-containing layer 5 narrower than that of a shading part 3,the width of a picture element part formed betweenphotocatalyst-containing layers 5 at the later step becomes wider thanthat of an opening formed by this shading part 3 and, therefore, and aproblem such as color missing and the like hardly occur as describedabove.

And, by adhering an ink 14 between the photocatalyst-containing layersusing an ink jet apparatus 13, a picture element part 6 is formed (FIG.13(C)). Upon this, since an ink 14 is adhered directly on a transparentsubstrate 2, it is preferable that a transparent substrate 2 is aninkphilic region on the surface thereof and, more particularly, it ispreferable that the contact angle with a liquid having the surfacetension of 40 mN/m is less than 10 degrees, more preferably the contactangle with a liquid having the surface tension of 40 mN/m is not morethan 5 degrees, particularly preferably not more than 1 degree. This isbecause, by making a surface of a transparent substrate 2 into aninkphilic region, an ink 14 is uniformly spread over a transparentsubstrate and disadvantages such as color nonuniformity and the like donot occur.

By irradiating a surface on which a picture element part 6 is formedwith the energy after formation of the picture element part 6 (FIG.13(D)), the formation of a protecting layer 8 which is provided asnecessary becomes easy (FIG. 13(E)).

Also in this embodiment, since the energy to be irradiated, ink jetapparatus and various inks are similar to those of the aforementionedembodiments, the explanation thereof is omitted.

The Eleventh Embodiment

The eleventh embodiment of the present invention is a process forproducing a color filter which is the fifth embodiment of the presentinvention, and comprises:

(1) a step of providing a photocatalyst-containing layer having thewettability of the energy-irradiated part on a transparent substrate,which changes in a direction of reduction of the contact angle with aliquid, on a shading part forming portion on which a shading part is tobe formed on a transparent substrate;

(2) a step of coloring a part on the transparent substrate on which aphotocatalyst-containing layer is not formed with an ink jet system, toform a picture element part;

(3) a step of irradiating at least the aforementionedphotocatalyst-containing layer with the energy; and

(4) a step of forming a shading part on a photocatalyst-containing layerirradiated with the energy.

This process is explained using FIG. 6. a photocatalyst-containing layer5 is first formed on a transparent substrate 2 in a pattern like state.A method of forming this photocatalyst-containing layer 5 in a patternlike state can be performed by a method used in the aforementioned ninthembodiment. A position of this photocatalyst-containing layer to beformed is a shading part forming portion 9 on which a shading part 3 isto be formed. Then, an ink is adhered to a part on which aphotocatalyst-containing layer 5 is not formed, that is, a pictureelement part forming portion on which a picture element part is to beformed, using an ink jet apparatus or the like, to form a pictureelement part 6. Upon this, for the similar reasons to those of theaforementioned tenth embodiment, the wettability on a transparentsubstrate is preferably an inkphilic region. More particularly, it ispreferable that the contact angle with a liquid having the surfacetension of 40 mN/m is less than 10 degrees, more preferably the contactangle with a liquid having the surface tension of 40 mN/m is not morethan 5 degrees, particularly preferably not more than 1 degree.

And, after a photocatalyst-containing layer 5 is made into inkphilic byirradiation with the energy, a shading part 3 is formed on thisphotocatalyst-containing layer 5. Then, finally, a protecting layer 8 isformed as necessary.

In this embodiment, regarding the energy to be irradiated, an ink jetapparatus to be used and various inks, the aforementioned ones explainedon other embodiments can be used.

C. Color Liquid Crystal Panel

A color liquid crystal panel can be formed by combining the thusobtained color filter and an opposite substrate which is opposite tothis color filter, and encapsulating a liquid crystal compoundtherebetween. The thus obtained color liquid crystal panel has theadvantages originated from the color filter of the present invention,that is, advantages that color nonuniformity and color missing do notoccur, and it is advantageous in a respect of cost.

The present invention is not limited to the aforementioned embodiments.The aforementioned embodiments are merely illustrative and whatsoeverhas the substantially same construction as that described in claims andexerts the same action and effects are included in the presentinvention.

EXAMPLE

The present invention is explained in detail by means of the followingexamples.

Example 1

1. Formation of Photocatalyst-containing Layer

30 g of isopropylalcohol, 0.4 g of MF-160E (manufactured by TohchemProducts Co.), a main component of which is fluoroalkylsilane, 3 g oftrimethoxymethylsilane (manufactured by Toshiba Silicone Co., Ltd.,TSL8113) and 20 g of a dispersion of titanium oxide which isphotocatalyst in water ST-K01 (manufactured by Ishihara Sangyo Kaisha,Ltd.) were mixed and stirred at 100° C. for 20 minutes. This was dilutedthree-times with isopropylalcohol to obtain a composition for aphotocatalyst-containing layer.

The composition was applied on a glass transparent substrate with a spincoater and dried at 50° C. for 10 minutes to form a transparentphotocatalyst-containing layer (thickness 0.2 μm).

2. Confirmation of Formation of an Inkphilic Region by Exposure

The pattern-exposure was performed for 50 seconds on thisphotocatalyst-containing layer at an illuminance of 70 mW/cm² with amercury lamp (wavelength 365 nm) via a mask, an exposed part was formedand the contact angles with a liquid of an unexposed part and an exposedpart were measured. At unexposed part, the contact angle with a liquidhaving the surface tension of 30 mN/m (manufactured by Junsei ChemicalCo., Ltd., ethylene glycol monoethyl ether) was measured (after 30seconds from dropping of a droplet from a microsyringe) of using acontact angle measuring apparatus (manufactured by Kyowa InterfaceScience Co., Ltd., type CA-Z) and found to be 30 degrees. As an exposedpart, the contact angle with a liquid having the surface tension of 50mN/m (manufactured by Junsei Chemical Co., Ltd., wettability indexstandard solution No. 50) was measured in a similar method and found tobe 7 degrees. Like this, an exposed part was converted into an inkphilicregion and it was confirmed that the pattern formation is possible dueto the difference in the wettability between an exposed part and anunexposed part.

3. Formation of Shading Part

Then, a photocatalyst-containing layer was formed on a transparentsubstrate according to the same manner as that described above. Thisphotocatalyst-containing layer was exposed (at an illuminance of 70mW/cm² for 50 seconds) with a mercury lamp (wavelength 365 nm) via amask for a shading part on which an opening pattern(opening line width30 μm) is provided in the matrix-like, convert an exposed part for ashading part into an inkphilic region (not greater than 7 degrees interms of the contact angle with a liquid having the surface tension of50 mN/m).

On the other hand, a mixture having the following composition was heatedto 90° C. to dissolve, centrifuged at 12000 rpm and, thereafter,filtered with a 1 μm glass filter. To the resulting aqueous coloredresin solution was added 1% by weight of ammonium dichromate as across-linking agent to prepare a coating material for a shading part.

Carbon black (manufactured by Mitsubishi Chemical Corporation, #950) . .. 4% by weight

Polyvinyl alcohol (manufactured by Nippon Synthetic Chemicals Co., Ltd.,Gosenol AH-26) . . . 0.7% by weight

Ion exchanged water . . . 95.3% by weight

Then, the aforementioned coating material for a shading part was appliedon the whole surface of a photocatalyst-containing layer with a bladecoater. The thus applied coating material for a shading part wasrepelled from an unexposed part of a photocatalyst-containing layer andit was selectively adhered to only an exposed part for a shading part.Thereafter, drying was performed at 60° C. for 3 minutes and exposurewas performed with a mercury lamp to cure a coating material for ashading part, which was further heat-treated at 150° C. for 30 minutesto form a shading part.

4. Formation of Picture Element Part

Then, the whole surface of a photocatalyst-containing layer on which ashading part is formed is exposed to convert a picture element partforming portion into an inkphilic. Then, a UV-curing typemultifunctional acrylate monomer ink of each RGB color containing 5% byweight of a pigment, 20% by weight of a solvent, 5% by weight of aninitiator and 70% by weight of a UV-curing resin was adhered to anexposed part of a picture element part which was converted intoinkphilic to color it using an ink jet apparatus, and UV-treated to cureit. Here, as regards each of red, green and blue ink, as a solvent,polyethylene glycol monometylethyl acetate was used and, as aninitiator, Ilgacular 369 (trade name, manufactured by Chiba SpecialityChemicals Co., Ltd.) was used and, as a UV-curing resin, DPHA(dipentaerythritol hexaacrylate, manufactured by Nippon Kayaku Co.,Ltd.) was used. In addition, regarding a pigment, as a red ink, C.I.Pigment Red 177 was used and, as a green ink, C. I. Pigment Green 36 wasused and, as a blue ink, C. I. Pigment Blue 15+C. I. Pigment Violet 23was used.

5. Formation of a Protecting Layer

A protecting layer was formed by applying a two-pack mixing typethermally curing agent (SS7265 manufactured by Nippon Synthetic RubberCo., Ltd.) with a spin coater and curing-treated at 200° C. for 30minutes to obtain a color filter. The resulting color filter was of thehigh quality free from color missing or color nonuniformity at a pictureelement part.

Example 2

1. Formation of a Photocatalyst-containing Layer

According to the similar manner to that in Example 1, the similarphotocatalyst-containing layer was formed on a transparent substrate onwhich a shading part was formed with chromium by a sputtering method.

2. Formation of a Picture Element Part

Then, an exposed part for a picture element part was pattern-exposedfrom a photocatalyst-containing layer side by a mercury lamp (wavelength365 nm, 70 mW/cm²) for 50 seconds via a mask for a picture element partto convert into an inkphilic region (not more than 7 degrees in terms ofa contact angle with a liquid having the surface tension of 50 mN/m).

A UV-curing type multifunctional acrylate monomer ink of each RGB colorcontaining 5% by weight of a pigment, 20% by weight of a solvent, 5% byweight of an initiator and 70% by weight of a UV-curing resin wasadhered to this exposed part of a picture element part which wasconverted into inkphilic to color it using an ink jet apparatus andUV-treated to cure it. Here, as regards each of red, green and blue ink,as a solvent, polyethylene glycol monometylethyl acetate was used and,as an initiator, Ilgacular 369 (trade name, manufactured by ChibaSpeciality Chemicals Co., Ltd.) was used and, as a UV-curing resin, DPHA(dipentaerhythritol hexaacrylate, manufactured by Nippon Kayaku Co.,Ltd.) was used. In addition, regarding a pigment, as a red ink, C.I.Pigment Red 177 was used and, as a green ink, C. I. Pigment Green 36 wasused and, as a blue ink, C. I. Pigment Blue 15+C. I. Pigment Violet 23was used.

3. Formation of a Protecting Layer

A protecting layer was formed by applying a two-pack mixing typethermally curing agent (SS7265 manufactured by Nippon Synthetic Rubber,Ltd.) with a spin coater and curing-treated at 200° C. for 30 minutes toobtain a color filter. The resulting color filter was of the highquality free from color missing or color nonuniformity of a pictureelement part as in Example 1.

Example 3

1. Formation of a Photocatalyst-containing Layer

3 g of isopropylalcohol, 0.014 g of fluoroalkylsilane (manufactured byTohchem Products Co.; MF-160E (trade name), a 50% by weight solution ofisopropyl ether ofN-[3-(trimethoxysilyl)propyl]-N-ethylperfluorooctabesulfonamide), 2 g ofa titanium oxide sol (manufactured by Ishihara Sangyo Kaisha, Ltd.;STS-01 (trade name)), 0.6 g of a silica sol (manufactured by Nipponsynthetic Rubber, Ltd.; Glaska HPC7002 (trade name)) and 0.2 g ofalkylalkoxysilane (manufactured by Nippon synthetic Rubber, Ltd.;HPC402II (trade name)) were mixed and stirred at 100° C. for 20 minutes.This solution was applied on a non-alkali glass substrate having thethickness of 0.7 mm by a spin coating method to obtain aphotocatalyst-containing layer having the thickness of 0.15 μm.

2. Confirmation of Formation of an Inkphilic Region by Exposure andReduction of an Amount of Fluorine

The surface of this photocatalyst-containing layer was irradiated withthe ultraviolet light for 2 minutes at an illuminance of 70 mW/cm² (365nm) by a super high pressure mercury lamp via a lattice-like photomask,and a contact angle with n-octane (surface tension of 21 mN/m) wasmeasured with a contact angle measuring apparatus (manufactured by KyowaInterface Science Co., Ltd., type CA-Z) and found to be 52 degrees at anunexposed part and 0 degrees at an exposed part.

An unexposed part and an exposed part were elementally-analyzed with aX-ray photoelectron spectroscopy apparatus (V. G. Scientific Co., Ltd.,ESCLAB220-I-XL). The quantitative calculation was performed with theSherry correction and Scofield relative sensitivity correction to obtainthe results which were expressed as a relative value of weight relativeto 100 of titanium (Ti) and found to be fluorine (F) 1279 relative totitanium (Ti) 100 at an unexposed part and fluorine (F) 6 relative totitanium (Ti) 100 at an exposed part.

From these results, it was found that, by exposing aphotocatalyst-containing layer, a ratio of fluorine in the surface of aphotocatalyst-containing layer is reduced and, thereby, the surface isconverted from ink-repellent into inkphilic.

What is claimed is:
 1. A color filter comprising a transparentsubstrate, a picture element part provided on the transparent substrateby a pattern of a plurality of colors with an ink jet system, a shadingpart provided on a border part of the picture element part, and aphotocatalyst-containing layer, provided for forming the picture elementpart or the picture element part and the shading part, comprising atleast a photocatalyst and a binder, and having the wettability which ischanged so that a contact angle with a liquid is reduced by an energyirradiation.
 2. The color filter according to claim 1, wherein thepicture element part is provided on the photocatalyst-containing layer.3. The color filter according to claim 2, wherein the shading part isformed on the transparent substrate, the photocatalyst-containing layeris provided on at least the shading part and on a picture element partforming portion which is a part on the transparent substrate, on whichthe picture element part is to be formed.
 4. The color filter accordingto claim 3, wherein a width of the picture element part formed on thephotocatalyst-containing layer is wider than that of an opening formedby the shading part.
 5. The color filter according to claim 3, whereinan ink-repellent convex part is formed on a surface of thephotocatalyst-containing layer provided on the shading part.
 6. Thecolor filter according to claim 5, wherein a width of the ink-repellentconvex part is formed narrower than that of the shading part.
 7. Thecolor filter according to claim 2, wherein the photocatalyst-containinglayer is formed on the transparent substrate and the picture elementpart and a shading part are provided at a position on thephotocatalyst-containing layer.
 8. The color filter according to claim2, wherein the shading part is provided on the transparent substrate,and the photocatalyst-containing layer is provided on a picture elementpart forming portion which is a part on the transparent substrate, onwhich the picture element part is to be formed and the picture elementpart is formed on the photocatalyst-containing layer.
 9. The colorfilter according to claim 1, wherein the photocatalyst-containing layeris provided on a border part of the picture element part.
 10. The colorfilter according to claim 9, wherein the shading part is formed on thetransparent substrate, the photocatalyst-containing layer is formed onthe shading part and the picture element part is formed between thephotocatalyst-containing layer.
 11. The color filter according to claim10, wherein a width of the photocatalyst-containing layer is formednarrower than that of the shading part.
 12. The color filter accordingto claim 9, wherein the photocatalyst-containing layer is formed on ashading part forming portion which is a part on the transparentsubstrate, on which a shading part is to be formed, the shading part isformed on the wettability-variable layer, and the picture element partis formed between the shading parts.
 13. The color filter according toclaim 9, wherein the wettability of the transparent substrate is lessthan 10 degrees as a contact angle with a liquid having surface tensionof 40 mN/m.
 14. The color filter according to claim 1, wherein thephotocatalyst-containing layer contains fluorine and thephotocatalyst-containing layer is formed so that the fluorine content ina surface of the photocatalyst-containing layer is reduced by an actionof the photocatalyst upon irradiating the photocatalyst-containing layerwith the energy as compared with before the energy irradiation.
 15. Thecolor filter according to claim 14, wherein the fluorine content in apart in which the fluorine content is reduced by irradiating thephotocatalyst-containing layer with the energy is 10 or less relative to100 of the fluorine content of a part not irradiated with the energy.16. The color filter according to claim 1, wherein the photocatalyst isone or more substances selected from the group consisting of titaniumoxide (TiO₂), zinc oxide (ZnO), tin oxide (SnO₂), strontium titanate(SrTiO₃), tungsten oxide (WO₃), bismuth oxide (Bi₂O₃) and iron oxide(FeO₃).
 17. The color filter according to claim 16, wherein thephotocatalyst is titanium oxide (TiO₂).
 18. The color filter accordingto claim 17, comprising the photocatalyst-containing layer in whichfluorine element is contained in a surface of thephotocatalyst-containing containing layer at rate of 500 or morerelative to 100 of Ti element as determined by a X-ray photoelectronspectroscopy.
 19. The color filter according to claim 1, wherein thebinder is organopolysiloxane having a fluoroalkyl group.
 20. The colorfilter according to claim 1, wherein the binder is organopolysiloxanewhich is a hydrolyzed and condensed compound or co-hydrolyzed andcondensed compound of one or more of silicon compounds represented byY_(n)SiX_((4−n)) wherein Y represents alkyl group, fluoroalkyl group,vinyl group, amino group, phenyl group or epoxy group, X representsalkoxyl group or halogen, and n is an integer of 0 to
 3. 21. The colorfilter according to claim 20, wherein a silicon compound having afluoroalkyl group among the silicon compounds constituting theorganopolysiloxane is contained at an amount of 0.01 mol % or more. 22.The color filter according to claim 1, wherein a contact angle with aliquid having the surface tension of 40 mN/m on thephotocatalyst-containing layer is not less than 10 degrees at a partirradiated with the energy.
 23. The color filter according to claim 1,wherein the picture element part colored with an ink jet system is apicture element part colored with an ink jet system using a UV-curingink.
 24. A liquid crystal panel comprising a color filter according toclaim 1 and a substrate which are opposite to the color filter, whereina liquid crystal compound is encapsulated between both substrates.